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SQL tutorials 17: SQL Primary Key constraint,  Drop primary Key
 
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Blog link: http://www.rebellionrider.com/sql-primary-key.htm SQL tutorial on Primary key / SQL Primary key, In this tutorial you will learn about simple primary key, composute primary key, how to drop primary key. defining primary key using create table and alter table along with many other things. Tool used in this tutorial is SQL Developer. This tutorial series is part of SQL expert exam certification training. if you are preparing for SQL certification you can use my tutorials. This SQL Tutorial is a part of free training. Copy Cloud referral link || Use this link to join copy cloud and get 20GB of free storage https://copy.com?r=j7eYO7 Contacts E-Mail [email protected] Twitter https://twitter.com/rebellionrider Instagram http://instagram.com/rebellionrider Facebook. https://www.facebook.com/imthebhardwaj Linkedin. http://in.linkedin.com/in/mannbhardwaj/ Thanks for linking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com So Primary Key There are two types of Primary keys First is Simple primary Key: Primary key which Involves only one column and Second is Composite Primary Key: Primary Key which involves more than one column. We will start with Simple primary key. You can create Primary key either with Create Table statement of by using Alter table Statement. Let's define simple primary key using create table statements. With create table statement we can either define primary key at column level or at table level. We will start with defining Primary key at column level using create table statement. You just have to put keyword Primary key after data type and size of column while defining a column of a table. Here oracle server will create a primary key on product id with default constraint name which will be slightly difficult to understand. You can give your own name to your constraint which is also a good practice.
Views: 96853 Manish Sharma
CREATE TABLE WITH CONSTRAINTS - ORACLE - SQL
 
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Create table , add constraints : primary key constraint, foreign key constraint, check constraint, unique constraint, specifying the table space for index, modifying table, dropping table Oracle 10g
Views: 9806 R.N.A. Creation
Oracle SQL Tutorial 13 - How to Add Column Constraints (Attributes)
 
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So far, we have this table declaration: CREATE TABLE users( user_id NUMBER, username VARCHAR(50 CHAR) first_name VARCHAR2(50 CHAR), last_name VARCHAR2(50 CHAR) ) We can run this command see that it works. As we are learning though, we are going to want to be able to recreate our table with different settings and such, but if you try to run this command, it will complain that the table already exists. So we first need to delete this table before we start editing settings. When we get more experienced, we will learn about ways to edit the structure of a table that already exists. To fix this, we can get rid of the table using the DROP TABLE command: DROP TABLE users You can run this every time if you need to practice by adding a semicolon after it. This is how you can tell Oracle that you are putting in another command after it. This is known as a delimiter. When you run the script, it is going to run both commands. Now we can go through and reconsider our table structure. This is fine for starting out because we don't have any important data in our database, but once your database is in production you are not going to want to just drop tables. In the last video we discussed different constraints that you can apply to columns in a database table, but how do you actually apply these when you are creating a table? The first way you define constraints is to put them right after the column in your CREATE TABLE statement. CREATE TABLE users( username VARCHAR2(50 CHAR) NOT NULL ) When we define constraints this way, we usually say we are adding column attributes. If you have two constraints you want to add, you just put one after the other with spaces in between. There is no particular order that is required. CREATE TABLE users( username VARCHAR2(50 CHAR) NOT NULL UNIQUE ) In this situation we have already given the column the NOT NULL and UNIQUE attributes, so we should consider making this a primary key: CREATE TABLE users( username VARCHAR2(50 CHAR) PRIMARY KEY ) As you can see, adding column attributes is super easy. We can add a default like this: CREATE TABLE users( username VARCHAR2(50 CHAR) PRIMARY KEY, account_balance NUMBER DEFAULT 0 ) Note that now we need the comma after the first row. There are a few constraints we did not talk go through an example, specifically foreign keys and check constraints. We will be adding these constraints to our database in future videos. In the mean time, I have a thought for you… Many people prefer to name their column constraints. That way, we can refer to certain constraints by name. For example, we might have a primary key constraint that could be named users_pk. The way we are creating these constraints does not allow for this feature, so in the next video we are going to be discussing different ways to create constraints. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me on Patreon! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 17592 Caleb Curry
Oracle SQL Tutorial 14 - Column-Level and Table-Level Constraints
 
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In the previous video we talked about adding constraints at the column-level. We made it nice and simple by only requiring a few keywords, but the problem we were having is that we could not assign a name to the constraint, which many people like to do so we can reference easily if we need to at a later time. To do this, it requires a little bit more typing, but it will give us extra flexibility and many consider it to be the higher quality approach to adding constraints. Let's go though a simple example. Let's say we have a users table with a user_id column that we want to make a primary key. We will create the table like this: CREATE TABLE( user_ id NUMBER PRIMARY KEY ) Instead of adding the PRIMARY KEY keywords after the data type, we add: CONSTRAINT user_pk PRIMARY KEY Now, we have assigned the name user_pk to this constraint. You can do the same with other constraints, such as UNIQUE. The syntax would be CONSTRAINT username_un UNIQUE. The other way to create constraints requires to put all of our constraints at the bottom of our table creation rather than inline with the column. This type of constraint is known as a table-level constraints. To make a column a primary key using table-level constraints, we add it to the CREATE TABLE command as if it is another row and use the CONSTRAINT keyword to tell Oracle that what is coming is a constraint, not a column in our table. CREATE TABLE users( user_id NUMBER, username VARCHAR2(50 CHAR), CONSTRAINT username_un UNIQUE (username), CONSTRAINT users_pk PRIMARY KEY (user_id) ) The primary differences here is that you have to put the column you are talking about in parenthesis after the PRIMARY KEY keyword. That's because it's at the end of the table and you need a way to tell it what column you are talking about. The option of putting it at the end of the table has the added benefit in this situation because if we needed to have a primary key that is the combination of multiple columns, we can do that by just adding the other column in the PRIMARY KEY parenthesis right after a comma. In summary, there are three ways to make constraints. The first is at the column level, unnamed. The second is at the column level, named. The third is at the table level, also named. In the next video we are going to create a named constraint in Oracle SQL Developer, so stay tuned and be sure to subscribe! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 13097 Caleb Curry
CREATE table and Integrity Constraint (Example in SQL) | DBMS
 
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Join discussion: http://www.techtud.com/video-illustration/illustration-create-table IMPORTANT LINKS: 1) Official Website: http://www.techtud.com/ 2) Virtual GATE: http://virtualgate.in/login/index.php Both of the above mentioned platforms are COMPLETELY FREE, so feel free to Explore, Learn, Practice & Share! Our Social Media Links: Facebook Page: https://www.facebook.com/techtuduniversity Facebook Group: https://www.facebook.com/groups/virtualgate Google+ Page: https://plus.google.com/+techtud/posts Last but not the least, SUBSCRIBE our YouTube channel to stay updated about the regularly uploaded new videos.
Views: 9172 Techtud
SQL Create Database, Create Table, Constraints in Table - Theory
 
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SQL Create Database, Create Table, Constraints in Table - Theory For Students of B.Tech, B.E, MCA, BCA, B.Sc., M.Sc., Courses - As Per IP University Syllabus and Other Engineering Courses
Oracle SQL Tutorial 15 - How to Add Primary Key Constraints
 
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The goal of this video is to take the CREATE TABLE statement we have and walk through the different ways to create primary keys. This and foreign keys are the most common constraints, so we need to make sure that you have this one down. Once we have a more complex database design with multiple tables, we will learn the proper way to create foreign keys. For now, I am going to keep all of our constraints at the column level, unnamed. The only exception is the primary key, because that is what we are focusing on in this video. The first way to create the primary key is at the column level, unnamed. The primary key is very important because it what we use to distinguish rows from one another. Every table you create is going to need a primary key, and I suggest putting a lot of effort into making sure your keys are set up correctly and organized. --Delete the table if needed: DROP TABLE users; CREATE TABLE users( user_id NUMBER PRIMARY KEY, username VARCHAR2(50 CHAR) NOT NULL UNIQUE ) The next way is at the column level, but named: --Delete the table: DROP TABLE users; CREATE TABLE users( user_id NUMBER CONSTRAINT users_pk PRIMARY KEY, username VARCHAR2(50 CHAR)NOT NULL UNIQUE ) The general naming convention here is the table name followed by an underscore, followed by pk for primary key. Finally, the third way, which is at the table level, is the way we are going to create our primary key: --Delete the table: DROP TABLE users; CREATE TABLE users( user_id NUMBER, username VARCHAR2(50 CHAR) NOT NULL UNIQUE, CONSTRAINT users_pk PRIMARY KEY (user_id) ) Now, once you've created these constraints, you can use Oracle SQL Developer to find these constraints. Open your databases in the connections tab and find the table in the Tables folder. Double click your table and travel to the Constraints tab. You can tell here that the UNIQUE constraint still exists in this table, but it has a pretty disgusting name. It kind of wants to make me puke. Referencing that constraint in the future with that wacky name would be a burden. Engrave these three options in your head so that you can use any of them whenever you need and can read other peoples' code. Thank you for sticking with the series thus far. In the next video, we will be…doing something. See you then! :) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me on Patreon! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 12786 Caleb Curry
SQL tutorials 18: SQL Foreign Key Constraint
 
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SQL Tutorial 18: SQL foreign key constraint. Topic covered in this tutorial 1. Defining SQL foreign key using create table at column level 2. Defining SQL foreign key using create table at table level 1. Defining SQL foreign key using Alter Table statement Links Website article: http://www.rebellionrider.com/sql-foreign-key.htm Primary key tutorial: http://www.rebellionrider.com/sql-foreign-key.htm Create Table Tutorial: http://www.rebellionrider.com/sql-create-table.html Tool used in this tutorial is SQL Developer. This tutorial series is part of SQL expert exam certification training. if you are preparing for SQL certification you can use my tutorials. This SQL Tutorial is a part of free training. Copy Cloud referral link || Use this link to join copy cloud and get 20GB of free storage https://copy.com?r=j7eYO7 Contacts E-Mail [email protected] Twitter https://twitter.com/rebellionrider Instagram http://instagram.com/rebellionrider Facebook. https://www.facebook.com/imthebhardwaj Linkedin. http://in.linkedin.com/in/mannbhardwaj/ Thanks for linking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com Foreign key is an Input/output data constraint which is also known as referential integrity constraint. Foreign key represent a link or say a relationship between columns of tables. Similar to primary key constraint Foreign Key constraint is also of two types. Simple Foreign key constraint and Composite Foreign key constraint. Constraint which involves only one column in foreign key in child table and one column in reference key in parent table is called Simple Foreign Key. While the constraint which involves more than one column in foreign key in child table and more than one column in reference key in the parent table is called Composite Foreign Key.
Views: 98900 Manish Sharma
Oracle SQL Tutorial 18 - How to Create Foreign Keys
 
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In this video we are going to be creating foreign keys. I highly recommend watching the previous video before you watch this one. Essentially, we are creating a very simple database for a system where we can create projects and add people to those projects. We started with the users table: --Delete the table if needed: --DROP TABLE users; CREATE TABLE users( user_id NUMBER, username VARCHAR2(50 CHAR) UNIQUE, CONSTRAINT users_pk PRIMARY KEY (user_id) ); Now we are going to create a table for projects with a column that is a foreign key to the username. We're going to want to make this match data types: CREATE TABLE projects( project_id NUMBER, project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) ) Next, we need to add the column attributes we decided on last video: CREATE TABLE projects( project_id NUMBER, project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL ) NOT NULL because we want every project to have a creator, but we are not labeling UNIQUE because that means we could only have a specific username once in the table. We want to allow a user to create multiple projects. We also need to add a primary key: CREATE TABLE projects( project_id NUMBER, project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL, CONSTRAINT projects_pk PRIMARY KEY (username) ) Now, the question that remains is, how can I tell Oracle that I want the username to reference the username column of the other table? We have to make a foreign key constraint. As you've learned from the previous videos, there are about three ways to create constraints. You can do it inline at the column level, unnamed. You can do it at the column level, named, and you can do it at the Table level, named. Usually the table-level is preferred, but I will quickly remind you how to do all three again. CREATE TABLE projects( project_id NUMBER, project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL REFERENCES users (username), CONSTRAINT projects_pk PRIMARY KEY (project_id) ) This works, but if we want to name it, we should do this: CREATE TABLE projects( project_id NUMBER, project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL CONSTRAINT projects_users_fk REFERENCES users (username), CONSTRAINT projects_pk PRIMARY KEY (project_id) ) This works, but the preferred method is to do it at the table level: CREATE TABLE projects( project_id NUMBER, project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL, CONSTRAINT projects_pk PRIMARY KEY (project_id), CONSTRAINT projects_users_fk FOREIGN KEY (creator) REFERENCES users (username) ) Great! So you've learned how to create a foreign key, now we can see it inside of Oracle SQL Developer. One important thing when it comes to foreign keys is what happens when have data in your database and you try to delete the parent row that a row in the child table references? In the next video we are going to configure that using ON DELETE. See you all then and if you enjoy this series, please do me a huge favor by liking the video and subscribing to my YouTube channel. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ HELP ME! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 18752 Caleb Curry
Oracle Database11g tutorials 14 : How to CREATE TABLE using sql developer and command prompt
 
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Oracle Database11g tutorials 14 How to Create table using command prompt and Create table using sql developer Blog Link http://bit.ly/1TkY4Oe Time Line 0:25 Introduction of Tables in Database 1:03 What is Create Table (Introduction of create table) 1:30 Syntax of Create Table 2:08 How to create table using Command Prompt 4:55 How to create table using SQL Developer Links for Oracle Database tutorials 4: database connectivity using SQL developer and command prompt http://youtu.be/wSqoXRlXDUU You can have indepth knowledge about SQL create table here http://www.rebellionrider.com/sql-create-table.html Tool used in this tutorial is command prompt. This tutorial series is part of SQL expert exam certification training. if you are preparing for SQL certification you can use my tutorials. This SQL Tutorial is a part of free training. Copy Cloud referral link || Use this link to join copy cloud and get 20GB of free storage https://copy.com?r=j7eYO7 Contacts E-Mail [email protected] Twitter https://twitter.com/rebellionrider Instagram http://instagram.com/rebellionrider Facebook. https://www.facebook.com/imthebhardwaj Linkedin. http://in.linkedin.com/in/mannbhardwaj/ Thanks for linking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com Today in this oracle database tutorial we will see How to CREATE A TABLE. if we have to define a table in layman language then we can say that Tables are just a collection of Rows and Columns but In RDBMS tables are database objects which help in organizing data into ROWS and COLUMNS. We can also say that SQL tables are kind of data structure which are used by database for efficient storage of data. To create a table in our database we use SQL CREATE TABLE command. SQL CREATE TABLE is a type of DATA DEFINITION LANGUAGE also known as DDL. To Create a table in your schema you will require CREATE TABLE system privilege. In our future videos we will see what are system and object privileges and how to grant them to a user. Today for this video we will be using Sample schema HR which already has all the necessary privileges. Ohk Let's see the syntax. CREATE TABLE table name ( column name1 Data-Type(size), column name2 Data-Type(size), ..... ); CREATE TABLE is an oracle reserved word or say an Oracle key word whereas There are 3 different ways of creating a table in Oracle database. Creating a table using Command Line Interface (CLI) in Oracle database For demonstrating how to create table in oracle database using CLI, I'll be using Command prompt. Thats how we create table using command prompt. you can check your table structure by DESCRIBE command for that just write DESC and your table name. Like this Another way of creating a table is by using Graphic user interface (GUI) in Oracle database To demonstrate how to create table using GUI we will use SQL developer. Lets open our SQL developer I am connected to HR schema if you do not know how to create a connection to database using SQL developer please watch my oracle database tutorial 4 that explains database connectivity using SQL developer and command prompt. Link for this video is in the description below. So lets create a table. Creating a table using SQL developer is very easy we do not have to fire any query here. Let's start First of all right click on your connection in which you want to create a table and choose schema browser. This will open a separate schema browser pane or you can expend your connection by clicking this + sign and then right click on table and choose New Table. However I prefer working with schema browser so let's skip to schema browser pane here from the first drop-down list you can choose connection name and in the second drop down list you can choose what database objects you want to work with we want to create a table thus I'll choose table and then click this arrow here and choose option for new table Ok we have created a table wizard first of all give a unique name to your table and add some column as well. For this, click the green plus button. Now we already have a column so give it some name. Also choose a datatype from the list and specify any size you can check this not null column if in case you want to make this a mandatory column you can also specify default value and constraint If you want to make this column a primary key you can click here In my future video i'll show you what are these constraints and different ways of applying them on a column in a table. for this video we will concentrate on create table only so when you are done with all your columns click ok Thats your table You can double click on your table here and can see its structure. Thats it
Views: 168613 Manish Sharma
Oracle SQL Tutorial 19 - ON DELETE (SET NULL and CASCADE)
 
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Welcome everyone! Something you need to consider when you are creating foreign keys is what happens if you delete the parent? As a reminder, the parent is the row that has the value you are referencing in the row that has a foreign key. Why is this something important to consider? It's important because foreign keys need to protect us from two primary things, unacceptable INSERT statements, and unacceptable DELETE statements. Let's see what happens when we try to insert incorrect data into the table with the foreign key: INSERT INTO projects VALUES (1, 'Update website homepage', 'CalebCurry') The response tells us plainly that there is no such user in the users table. So this works correctly. Deleting data on the other hand works a bit differently because the database does not know what you want to do with the child row when you delete the parent from the parent table. By default, we will get an error message that prevents the parent from being deleted, but there are some other options. How do we configure this? This is where the ON DELETE statement comes in. We add the keywords ON DELETE right after the foreign key and then we can give it the option of CASCADE or SET NULL. CASCADE means that if we delete the parent, we are also going to delete the child. In our situation what that means is that if somebody creates a project in our project table and then that persons account gets deleted, all of the projects he owns will also be deleted. CASCADE: CREATE TABLE projects( project_id NUMBER, Project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL, CONSTRAINT projects_pk PRIMARY KEY (project_id), CONSTRAINT projects_users_fk FOREIGN KEY (creator) REFERENCES users (username) ON DELETE CASCADE ) SET NULL will take the value in the child table and get rid of it. What you are left with is NULL. This means that we have an orphaned child. The first thought you might have is that it is a bad thing to have an orphaned child, but in databases that is not always so. In our application if we had it set to SET NULL, when a user account gets deleted the projects would remain in existence they would just lack a creator. This might be a good thing if you are concerned about the long term survival of a project, this might be the route you want to go. It ultimately depends on the application purpose. If you don't like CASCADE or SET NULL, you can leave the entire ON DELETE statement and just have Oracle throw an error when a parent is deleted. As for us, we are going to use ON DELETE CASCADE. We need to use this with extreme caution. If you are not careful, someday you will run a delete a row and that will cascade through you database deleting a bunch of stuff you didn't want to delete. Stuff happens, so make sure you back up your database every once in eternity. Now, in the last video we started with a database design that had three tables. We've only created two in this video. In the next video we are going to create the next one, which is a little special. Then we'll finish things up by adding some indexes. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me on Patreon! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 13156 Caleb Curry
Oracle SQL Tutorial 11 - CREATE TABLE
 
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The way you create a table is to use the CREATE TABLE command. CREATE TABLE users() So in this situation, the name comes right after the TABLE keyword. The next thing we do is put all of the columns on a line that we want to put in our table. CREATE TABLE users( user_id, username, first_name, last_name ) Notice the naming conventions here. For this series we are going to make columns with what is known as snake casing. This is where each individual word is separated by an underscore. if you have more than one column, all of them have to have commas except the last one. The comma is a way to say that another column is coming, so you don't need to do it on the last one. Now you would think we were done, but we also have to say what data type each column is. Later we will extensively discuss data types so we can focus on them exclusively. For now, here are the data types we are going to use: CREATE TABLE users( user_id NUMBER, username VARCHAR2(50), first_name VARCHAR2(50), last_name VARCHAR2(50) ) Now, inside of the parenthesis for varchar2, we pass in a number... This is the max length of the string. But the question is, what is it measured in? The default is actually in bytes, not characters. For example if we have the string hello, it is 5 characters, but it might take up a total of 10 bytes of storage. So I would recommend adding the keyword char right after the number so it defaults to 50 characters, not bytes. CREATE TABLE users( user_id NUMBER, username VARCHAR(50 CHAR), first_name VARCHAR2(50 CHAR), last_name VARCHAR2(50 CHAR) ) This will work to create a table, but it's really missing a lot of information… which column is the primary key? Are we adding any indexes? Is there any thing else we need to say about these columns? So as you can tell, we are making progress, but there is still so much to learn. The biggest gotcha to remember from this video is that the data type VARCHAR ends in a 2, stupid, right? who would end the name of something with a 2? Once again, this is Caleb from CalebTheVideoMaker2, and we will catch you in the next one! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ HELP ME! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 28103 Caleb Curry
Oracle Sql 4: alter table constraints
 
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add y drop check, unique, primary key
Views: 1518 tomas bonilla
SQL Tutorial - 8: Constraints in SQL
 
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In this tutorial we will discuss the various constraints available to us in SQL. We'll talk about Not Null, Default, Unique and Primary Key Constraints.
Views: 102553 The Bad Tutorials
Oracle SQL Tutorial   Creating constraints after Table Creation
 
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Oracle SQL Tutorial Creating constraints after Table Creation above tutorial lets u know how u can create constrains or apply constrains after creating a table
Views: 81 magan lal
02 of  13 - Oracle APEX 5 - Run SQL scripts to create tables, sequences, triggers and insert data
 
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A new series using APEX 18.1 is now available. https://youtu.be/65LExgaQMHI This video in the APEX 5 tutorial series shows how to use SQL Scripts (part of SQL Workshop) to run scripts that create tables, sequences (to generate unique values for primary keys), triggers and insert data (INSERT INTO statements). SQL scripts for this series are available to download at: http://web.nmsu.edu/~jkreie/oracle/DatabaseTopics.html or by request at http://db.kreie.net
Views: 46752 Jennifer Kreie
SQL Tutorial - Create Table with Constraints
 
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This video tutorial will show you how to create a table with constraints in Microsoft SQL Server. The video covers, data types of columns, NOT NULL constraints, PRIMARY KEY constraints, FOREIGN KEY constraints, CHECK constraints and DEFAULT constraints. Data types enforce limits to the what can inserted in to tables and constraints further build on this, for example if you wanted to add a column called age, the values will usually range from 0 - 100 so we could choose a data type of TINYINT which allows values of up to 255 but this means if you enter 255 this is still a valid age. We want to control this even further so we can add a CHECK constraint that will only allow values from 0 - 100. Check out the video for how to add this constraint. CREATE TABLE dbo.[Login] ( Username VARCHAR(30) NOT NULL CONSTRAINT PK_Login_Username PRIMARY KEY (Username) , [Password] VARCHAR(30) NOT NULL , LastUpdate DATETIME2 NOT NULL CONSTRAINT DF_Login_LastUpdate DEFAULT (CURRENT_TIMESTAMP) , [Status] CHAR(10) NOT NULL CONSTRAINT CK_Login_Status CHECK ([Status] IN ('Active', 'Inactive')) , CustomerID INT CONSTRAINT FK_Login_CustomerId FOREIGN KEY (CustomerId) REFERENCES Customers (CustomerId) )
Views: 647 BeardedDev
Oracle SQL Tutorial 21 - How to Create / Drop Indexes
 
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In the last video, we wrote up the SQL to create three tables: CREATE TABLE users( user_id NUMBER, username VARCHAR2(50 CHAR) UNIQUE, CONSTRAINT users_pk PRIMARY KEY (user_id) ); CREATE TABLE projects( project_id NUMBER, Project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL, CONSTRAINT projects_pk PRIMARY KEY (project_id), CONSTRAINT projects_users_fk FOREIGN KEY (creator) REFERENCES users (username) ON DELETE CASCADE ); CREATE TABLE project_users( project_id NUMBER NOT NULL REFERENCES projects (project_id) ON DELETE CASCADE, user_id NUMBER NOT NULL REFERENCES users (user_id) ON DELETE CASCADE, CONSTRAINT project_users_pk PRIMARY KEY (project_id, user_id) ); I'm going to increase the size of the users table a bit by adding a first and last name column. CREATE TABLE users( user_id NUMBER, username VARCHAR2(50 CHAR) UNIQUE, first_name VARCHAR2(50 CHAR), last_name VARCHAR2 (50 CHAR), CONSTRAINT users_pk PRIMARY KEY (user_id) ); But before we finish this design, we should consider indexing certain columns. What columns should we index? Well, as a reminder, the columns that are indexed by default are columns with the UNIQUE constraint, and those that are labeled as primary keys. Columns that are not indexed but often should be are those labeled as a foreign key. The column that jumps out the most to me is the creator column of the project table. It's the only foreign key that is not part of some index. Let's fix this by creating our first index. The way we do that is with the CREATE INDEX command. CREATE INDEX projects_creator_ix ON projects (creator) What naming convention are we following for the index? We are naming it by the table name, followed by an underscore, followed by the column, followed by an underscore, followed by an ix (for index). In this situation it does not apply, but if our foreign key column is labeled as UNIQUE, we can add the UNIQUE keyword like this: CREATE UNIQUE INDEX projects_creator_ix ON projects (creator) Now if you want to get rid of an INDEX, you can use this command: DROP INDEX projects_creator_ix Now, if we want to select data from the user table and the project table we can do that much faster. That's because the foreign key and column it references are both indexed and those are the columns we would do the join on. We will discuss how to do joins in a future video. So what are some potential problems with this database design? Overall, it is pretty good. With this design though we need to make sure there is no way for someone to update a user's username. In the next video we are going to discuss why. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me on Patreon! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 7533 Caleb Curry
SQL: Check Constraint
 
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In this tutorial, you'll learn how to make use of check constraint. PL/SQL (Procedural Language/Structured Query Language) is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database (since version 7), TimesTen in-memory database (since version 11.2.1), and IBM DB2 (since version 9.7).[1] Oracle Corporation usually extends PL/SQL functionality with each successive release of the Oracle Database. PL/SQL includes procedural language elements such as conditions and loops. It allows declaration of constants and variables, procedures and functions, types and variables of those types, and triggers. It can handle exceptions (runtime errors). Arrays are supported involving the use of PL/SQL collections. Implementations from version 8 of Oracle Database onwards have included features associated with object-orientation. One can create PL/SQL units such as procedures, functions, packages, types, and triggers, which are stored in the database for reuse by applications that use any of the Oracle Database programmatic interfaces. PL/SQL works analogously to the embedded procedural languages associated with other relational databases. For example, Sybase ASE and Microsoft SQL Server have Transact-SQL, PostgreSQL has PL/pgSQL (which emulates PL/SQL to an extent), and IBM DB2 includes SQL Procedural Language,[2] which conforms to the ISO SQL’s SQL/PSM standard. The designers of PL/SQL modeled its syntax on that of Ada. Both Ada and PL/SQL have Pascal as a common ancestor, and so PL/SQL also resembles Pascal in several aspects. However, the structure of a PL/SQL package does not resemble the basic Object Pascal program structure as implemented by a Borland Delphi or Free Pascal unit. Programmers can define public and private global data-types, constants and static variables in a PL/SQL package.[3] PL/SQL also allows for the definition of classes and instantiating these as objects in PL/SQL code. This resembles usage in object-oriented programming languages like Object Pascal, C++ and Java. PL/SQL refers to a class as an "Abstract Data Type" (ADT) or "User Defined Type" (UDT), and defines it as an Oracle SQL data-type as opposed to a PL/SQL user-defined type, allowing its use in both the Oracle SQL Engine and the Oracle PL/SQL engine. The constructor and methods of an Abstract Data Type are written in PL/SQL. The resulting Abstract Data Type can operate as an object class in PL/SQL. Such objects can also persist as column values in Oracle database tables. PL/SQL is fundamentally distinct from Transact-SQL, despite superficial similarities. Porting code from one to the other usually involves non-trivial work, not only due to the differences in the feature sets of the two languages,[4] but also due to the very significant differences in the way Oracle and SQL Server deal with concurrency and locking. There are software tools available that claim to facilitate porting including Oracle Translation Scratch Editor,[5] CEITON MSSQL/Oracle Compiler [6] and SwisSQL.[7] The StepSqlite product is a PL/SQL compiler for the popular small database SQLite. PL/SQL Program Unit A PL/SQL program unit is one of the following: PL/SQL anonymous block, procedure, function, package specification, package body, trigger, type specification, type body, library. Program units are the PL/SQL source code that is compiled, developed and ultimately executed on the database. The basic unit of a PL/SQL source program is the block, which groups together related declarations and statements. A PL/SQL block is defined by the keywords DECLARE, BEGIN, EXCEPTION, and END. These keywords divide the block into a declarative part, an executable part, and an exception-handling part. The declaration section is optional and may be used to define and initialize constants and variables. If a variable is not initialized then it defaults to NULL value. The optional exception-handling part is used to handle run time errors. Only the executable part is required. A block can have a label. Package Packages are groups of conceptually linked functions, procedures, variables, PL/SQL table and record TYPE statements, constants, cursors etc. The use of packages promotes re-use of code. Packages are composed of the package specification and an optional package body. The specification is the interface to the application; it declares the types, variables, constants, exceptions, cursors, and subprograms available. The body fully defines cursors and subprograms, and so implements the specification. Two advantages of packages are: Modular approach, encapsulation/hiding of business logic, security, performance improvement, re-usability. They support object-oriented programming features like function overloading and encapsulation. Using package variables one can declare session level (scoped) variables, since variables declared in the package specification have a session scope.
Views: 11316 radhikaravikumar
Oracle Constraints
 
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Oracle SQL Tutorials For Full Course Experience Please Go To http://mentorsnet.org/course_preview?course_id=4 Full Course Experience Includes 1. Access to course videos and exercises 2. View & manage your progress/pace 3. In-class projects and code reviews 4. Personal guidance from your Mentors
Views: 20129 Oresoft LWC
SQL: Foreign Key Creation
 
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In this tutorial, you'll learn how to create a foreign key column ....
Views: 37934 radhikaravikumar
Oracle Unique Constraint تعليم اوراكل
 
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by Mohamed El Desouki - محمد الدسوقى [email protected] Tel :00966 553450836 جامعة سلمان بن عبد العزيز - السعودية - الخرج How To Add Unique Constraint to Table. Unique كيف تستخدم قيد الــ Text Book: Fundamentals of Database Systems, 5th Edition, by Elmasri/Navathe, published by Addison-W oracle create table statement oracle drop table statement oracle constraints database constraints primary key constraint foreign key constraint check constraint null not null constraint unique constraint
SQL with Oracle 10g XE - Using CREATE TABLE to Build a Table
 
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In this video I use the CREATE TABLE command to create three tables: Books, Publisher, and Author. I use these three tables as sample data. The code I entered in is: CREATE TABLE BOOK ( BOOK_ID VARCHAR(4) PRIMARY KEY, ISBN_10 VARCHAR(10), ISBN_13 VARCHAR(13), TITLE VARCHAR(50), CATEGORY VARCHAR(15), PRICE DECIMAL(6,2), BINDING VARCHAR(1), PUB_DATE VARCHAR(4), AUTHOR_ID SMALLINT, PUBLISHER_ID SMALLINT ); CREATE TABLE PUBLISHER ( PUBLISHER_ID SMALLINT PRIMARY KEY, PUBLISHER_NAME VARCHAR(40) ); CREATE TABLE AUTHOR ( AUTHOR_ID SMALLINT PRIMARY KEY, AUTHOR_LAST VARCHAR(25), AUTHOR_FIRST VARCHAR(20) ); I have to create each table individually in the SQL commands window. This video is part of a series of videos with the purpose of learning the SQL language. For more information visit Lecture Snippets at http://lecturesnippets.com.
Views: 103197 Lecture Snippets
Oracle Join Tables تعليم أوراكل
 
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by Mohamed El Desouki - محمد الدسوقى [email protected] Tel :00966 553450836 جامعة سلمان بن عبد العزيز - السعودية - الخرج How to select data from more than one table using Join. كيفية الربط بين أكثر من جدول Text Book: Fundamentals of Database Systems, 5th Edition, by Elmasri/Navathe, published by Addison-W oracle create table statement oracle drop table statement oracle constraints database constraints primary key constraint foreign key constraint check constraint null not null constraint unique constraint insert into statement update statement delete statement select statement basic query where clause select where Like '%' Like '_' select where Like Join Tables inner join equi join
Oracle Foreign key Constraint تعليم اوراكل
 
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by Mohamed El Desouki - محمد الدسوقى [email protected] Tel :00966 553450836 جامعة سلمان بن عبد العزيز - السعودية - الخرج How To Combine two tables using Foreign Key Constraint.ربط الجداول بإستخدام قيد Text Book: Fundamentals of Database Systems, 5th Edition, by Elmasri/Navathe, published by Addison-W oracle create table statement oracle drop table statement oracle constraints database constraints primary key constraint foreign key constraint check constraint null not null constraint unique constraint
Oracle SQL Tutorial   Creating a table and its constraints   YouTube
 
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Oracle SQL Tutorial Creating a table and its constraints YouTube
Views: 51 magan lal
Create Table with constraint Not Null  in Oracle "انشاء جدول بقيد"
 
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Create table with a not null constraint and show how violation occurs. insure data integrity in the database Show how to get random sample data from http://www.generatedata.com/
Views: 199 Reda El Said
Oracle || Column level constraints & table level constrains by siva
 
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DURGASOFT is INDIA's No.1 Software Training Center offers online training on various technologies like JAVA, .NET , ANDROID,HADOOP,TESTING TOOLS , ADF, INFORMATICA,TABLEAU,IPHONE,OBIEE,ANJULAR JS, SAP... courses from Hyderabad & Bangalore -India with Real Time Experts. Mail us your requirements to [email protected] so that our Supporting Team will arrange Demo Sessions. Ph:Call +91-8885252627,+91-7207212428,+91-7207212427,+91-8096969696. http://durgasoft.com http://durgasoftonlinetraining.com https://www.facebook.com/durgasoftware http://durgajobs.com https://www.facebook.com/durgajobsinfo............
Introduction to Oracle: Application Express Table Creation
 
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Introduction to Oracle: Application Express Table Creation. See www.mathheals.com for more videos
Views: 5679 David Hays
constraint in dbms/sql - (null / notnull, check, default , unique, primary key constraints)
 
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constraint in sql with examples, null / notnull, check, default , unique, primary key constraints dbms constraints, DBMS videos. .................................................... GATE lectures on SIGNAL AND SYSTEM - by Shrenik Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI1qBFREKxhFbBR8veKrYj60 GATE lectures on ANALOG ELECTRONICS - by Shrenik Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI0SzA4wJDv7EqfgCHaRtunH&disable_polymer=true DIGITAL COMMUNICATION by Shrenik Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI0-af8Lr1S5Bwbv4_-kbi-4 DIGITAL LOGIC DESIGN - by Shrenik Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI0V04wTbaqUWvcvAE_B98Qj DSP by Shrenik Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI1VEDhEOVNHrTs_pzt684ou signal and system by SHRENIK JAIN https://www.youtube.com/playlist?list=PLfP-D1tg0DI2Fpj_oV4VvLax4JJVL_kW2 DBMS by Shrenik Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI0D1MSTRXFr1X6bb_ZI0E7W ANALOG ELECTRONICS by Shrenik Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI3HaJdHpBu7XX-m9c6mANZk ANALOG ELECTRONICS-2 by Shrenik Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI3tNQmWNnSrGydZ1tQUSMXy OPERATING SYSTEM -by SHRENIK JAIN https://www.youtube.com/playlist?list=PLfP-D1tg0DI1U3Xe4ynk6ocVQl2qKoDoB CONTROL SYSTEM - by Shrenik Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI1Cwku-ZLD-ofrsLHd5dHQy Engineering Maths https://www.youtube.com/playlist?list=PLfP-D1tg0DI0Kavkv81ZvQI8g7VSiVIm_ VLSI - by Shrenik Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI2Sn1DVzGdIeGyuIUjhJ9zp Limits and Continuity - by Siddhant Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI3Ln9qhdNlIbRR1gAqrGXH0 INTEGRATED CIRCUIT (IC) by Shrenik Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI1yEx1fdhqA8jR5WtCJvQN5 IMAGE PROCESSING - by Shrenik Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI2F_PAG8Z6WxZgqBK0jG_-D PROBABILITY by Shrenik Jain https://www.youtube.com/playlist?list=PLfP-D1tg0DI2KD99RmEobWaLiG4bZPNPN .................................................... ANY DOUBT ? ASK ON FB page . facebook link : https://www.facebook.com/studysimplified/ quora link : https://www.quora.com/profile/Shrenik-Jain-51
Views: 12566 Shrenik Jain
Learn SQL - SQL CONSTRAINTS
 
47:47
Learn Microsoft SQL from Scratch - https://www.udemy.com/microsoft-sql-server-database-concepts/?couponCode=YOUTUBE SQL Server Constraints: What are Constraints| Uses of Constraints |Types of Constraints |Null and Not Null |Primary Key|Foreign Key Check Default Unique Key Create Alter and Drop Constraint
SQL in Oracle 11g Tutorial #6: Create Table with Primary Key Constraint
 
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SQL in Oracle 11g Tutorial #6: Create Table with Primary Key Constraint. How to create the primary key in a table. Thanks for Watching my Channel “Learn TechToTech”. Please subscribe my channel for getting first updates after uploading video.Social Media pages of Channel are: 1. My Website : www.learnfromrakesh.com 2. My Twitter: https://twitter.com/LearnTechtotech 3. Facebook Page: https://www.facebook.com/LearnTechToTech 4. Blogger : https://learntechtotech.blogspot.in/ 5. Google+ : https://learntechtotech.blogspot.in/ 6. Pinterest : https://in.pinterest.com/LearnTechToTech/ 7. LinkedIn: https://www.linkedin.com/in/Learntechtotech/ Playlist of Different Technology: 1. Operating System : https://goo.gl/q6SfrW 2. Python Programming Language : https://goo.gl/L8b5dc 3. C Language : https://goo.gl/SwvDu9 4. C language for Placement: https://goo.gl/AaQBa4 5. Java: https://goo.gl/M8F2uy 6. MySql : https://goo.gl/vdJbHQ 7. Android Mobile Application Development: https://goo.gl/M6woaT 8. Kotlin Programming Language : https://goo.gl/GXE5cd 9. Go Programming: https://goo.gl/Ua3xYW 10. Internet of Things(IoT): https://goo.gl/f2afkY 11. Oracle 11g : https://goo.gl/zds8r2 12. C++ : https://goo.gl/C1psMT
Views: 59 Learn TechToTech
Constraint In Oracle PL SQL
 
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Constraint In Oracle PL SQL oracle tutorial for beginners A) UNIQUE CONSTRAINT : A unique constraint is uniquely defines a record. Its value is not repeated. It can be null. B)NOT NULL CONSTRAINT: Not null constraint restrict from inserting null values. If we want some columns does not take null values then we can use this constraint. C)CHECK CONSTRAINT: A check constraint allows you to specify a condition on particular column in a table. we can add our custom logical conditions. CREATE TABLE TEST2 ( ID VARCHAR2(10) UNIQUE, NAME VARCHAR2(50), DEPT VARCHAR2(10) NOT NULL, AGE NUMBER(10), CHECK (AGE BETWEEN 18 and 60) ); #techquerypond https://techquerypond.wordpress.com https://techquerypond.com https://twitter.com/techquerypond
Views: 173 Tech Query Pond
SQL Foreign Key Constraints
 
07:25
Jamie King of Neumont University showing what are and how to add foreign key constraints.
Views: 51950 Jamie King
SQL Tutorial - 9: Create Table Statement
 
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In this tutorial we'll learn to create tables in SQL using the CREATE TABLE Statement.
Views: 284739 The Bad Tutorials
MySQL Tutorial #16 in Hindi: Create Table with Constraints(NOT NULL, Unique, etc..)
 
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MySQL Tutorial #16 in Hindi: Create Table with Constraints(NOT NULL, Unique, AUTO INCREMENT, Default, Check) How to Create Sequence in MySQL MySQL tutorial for Beginners MySQL Installation Guide How to Install MySQL on windows 10
Oracle tutorial : How to create Id with AUTO INCREMENT in Oracle PL SQL
 
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Oracle tutorial: How to create Id with AUTO INCREMENT in Oracle oracle tutorial for beginners sequence in oracle identity key in sql In this Oracle tutorial , we can create an auto increment field using ‘sequence’ object that can be assigned as primary keys. Using Oracle ‘sequence’ object, you can generate new values for a column. An Oracle sequence is an object like a table or a stored procedure. Examples CREATE SEQUENCE SYSTEM.MYSEQ START WITH 1 MAXVALUE 999999999999999999999999999 MINVALUE 1 NOCYCLE CACHE 20 NOORDER; CREATE OR REPLACE TRIGGER TR_CITY BEFORE INSERT ON CITY FOR EACH ROW BEGIN SELECT LPAD(LTRIM(RTRIM(TO_CHAR(myseq.NEXTVAL))),10,'0') INTO :NEW.id FROM DUAL; END; / Subscribe on youtube: https://www.youtube.com/channel/UCpiyAesWNYOXSz5GPq8lbkA For more tutorial please visit #techquerypond https://techquerypond.wordpress.com https://twitter.com/techquerypond
Views: 8487 Tech Query Pond
Oracle SQL Tutorial 16 - Parent Child Relationships
 
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So far in this series we have discussed database design, creating tables, and constraints. We've brought up the concept of foreign keys, but we have not explained how to create them. That is the goal of this video and the upcoming videos. We want to study those foreign keys! Let's make them not so foreign. Let's learn the proper way to define a foreign key. As a reminder, a foreign key is a column that references a column of another table. The column it references must either be a primary key, or have the UNIQUE constraint. This means that every value inside of the column that is labeled as a foreign key, there must be that value in some row of the referenced column. As an example, imagine that we have the users table, and we have a table service_requests. We could have a column in the service_request that references a column in the users table. Usually this would be the primary key that is referenced, but there is nothing stopping you from referencing a unique column. Just for fun, let's go through an example using the username column. If we have a service_requests table, every single row within the table is going to be what some would consider an instance of a service_request. This means that the table columns are like the blueprint for what a service request looks like and then each row is an individual service request. If we have one of the columns labeled as a foreign key to the username of the users table, what does that mean practically? It means that for a single row, the value for that column must be a value that exists in the users table. We could have a service_request submitted by a user with the username of Yoloswagman. This means that there must be a row inside of the users table that has the value Yoloswagman for the username column. This brings up the concept of parent and child relationships. Yoloswagman in this situation is the parent, and his service request is the child. When we draw it out, it makes sense why a primary key must be UNIQUE. If we had two Yoloswagmans, the child would not know which column is the parent. The same applies if we were using IDs and we had So remember, always reference a primary key or a column with the UNIQUE constraint. Now, I have a question for you. Do foreign keys automatically have the UNIQUE constraint, just like primary keys? The answer is no. A parent row can have many child rows. It makes sense because the user could submit multiple service requests. Can we force the column to be unique? Absolutely. If that was the case, the user could only make one service request. Another question. Do foreign keys automatically have the NOT NULL constraint, just like primary keys? The answer is no. Essentially what this means is that a child could be created with no parent. Can we force the column to be NOT NULL? Absolutely. It is ok in some situations to allow the row to be null, but in this situation it makes no sense. It would be wise for us to add that constraint ourselves. So now that you understand some more differences between primary and foreign keys and parent child relationships, take all of these questions into consideration when you are creating foreign keys. In the next video, we are going to start a small project that is going to require multiple tables. We'll take a video to design our structure and then we'll get to creating those foreign keys in Oracle SQL Developer. Stick around and if you like these videos please be a serious supporter and subscribe to my channel. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ HELP ME! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 10772 Caleb Curry
Creating data model with Oracle SQL Developer  - Part 1
 
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This video tutorial is about creating a data model on existing schema using Oracle SQL Developer. This tutorial also includes adding referential constraints with data model and generating DDL from the data model.
Views: 4481 Subhroneel Ganguly
SelectTec | Aula Nº 13 | Primary key - Oracle SQL Developer
 
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primary key syntax: create table nome_tabela (coluna1 tipo not null, coluna2 tipo, constraint nome_pk primary key (coluna1) );
Views: 2574 SelectTec
Oracle SQL Tutorial For Beginners | Oracle SQL Online Training - Session 2
 
01:03:12
Course : Oracle SQL Online Training Mode of Training : Online Duration : 40 Hours Timings : Flexible Oracle SQL Online Training Demo Registration Link : http://svsoftsolutions.com/demo.aspx Introduction to SQL What is SQL? What Can SQL do? RDBMS SQL Syntax Database Tables SQL Statements Overview of Most Important SQL Commands SELECT UPDATE DELETE INSERT CREATE TABLE ALTER TABLE DROP TABLE CREATE INDEX DROP INDEX SQL SELECT Statement SELECT syntax Demo Database SELECT Column Example SELECT * Example SQL Distinct SELECT DISTINCT Statement SELECT DISTINCT Syntax SELECT DISTINCT Example SQL WHERE Clause WHERE Clause WHERE Clause Example Operators in the WHERE Clause SQL AND & OR Operators AND Operator Example OR Operator Example Combining AND & OR SQL ORDER BY ORDER BY Syntax ORDER BY Example ORDER BY DESC Example ORDER BY Several Column Examples SQL Insert Into INSERT INTO Syntax INSERT INTO Examples Insert Data into Specified Columns SQL UPDATE UPDATE Syntax UPDATE Example Watch out UPDATE statement. SQL DELETE DELETE Syntax DELETE Examples Delete All the Data SQL Aliases SQL Alias Syntax for Columns Alias Example for Table Columns Alias Example for Tables. SQL Joins Different SQL JOINs INNER JOIN LEFT OUTER JOIN RIGHT OUTER JOIN FULL OUTER JOIN SQL UNION UNION Syntax UNION Example UNION ALL Syntax UNION ALL Example SQL Insert Into Select INSERT INTO SELECT Syntax INSERT INTO SELECT Examples SQL Create Table CREATE TABLE Syntax CREATE TABLE Example SQL Constraints CREATE TABLE + CONSTRAINT Syntax NOT NULL Constraint UNIQUE Constraint UNIQUE Constraint on CREATE TABLE UNIQUE Constraint on ALTER TABLE To DROP a UNIQUE Constraint PRIMARY KEY Constraint PRIMARY KEY Constraint on CREATE TABLE PRIMARY KEY Constraint on ALTER TABLE To DROP a PRIMARY KEY Constraint FOREIGN KEY Constraint FOREIGN KEY Constraint on CREATE TABLE FOREIGN KEY Constraint on ALTER TABLE To DROP a FOREIGN KEY Constraint CHECK Constraint CHECK Constraint on CREATE TABLE CHECK Constraint on ALTER TABLE To DROP a CHECK Constraint DEFAULT Constraint on CREATE TABLE DEFAULT Constraint on ALTER TABLE To DROP a DEFAULT Constraint SQL Create Index CREATE INDEX Syntax CREATE UNIQUE INDEX Syntax CREATE INDEX Example SQL DROP Command The DROP INDEX Statement The DROP TABLE Statement The DROP DATABASE Statement The TRUNCATE TABLE Statement SQL ALTER Command The ALTER TABLE Statement ALTER TABLE Example Change Data Type Example DROP COLUMN Example SQL VIEWS CREATE VIEW Statement CREATE VIEW Syntax CREATE VIEW Examples CREATE OR REPLACE VIEW Syntax Dropping a View SQL NULL Values Working with NULL Values IS NULL IS NOT NULL SQL NULL Functions NVL COALESCE For more details visit our website : www.svsoftsolutions.com Or reach us @ USA : +1-845-915-8712 (Toll Free), India : +91-9642373173
Views: 51 SV Soft Solutions
Oracle Tutorials : 5 - CREATE / DROP TABLE
 
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Oracle Tutorials : 5 - CREATE / DROP TABLE
Views: 954 Meganadha Reddy
SQL Server 27 - How to Create FOREIGN KEY Constraints
 
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In the previous video we set up an entire table. The problem with this table is that the species column is just plain text. The problem with this is that there is a higher probability of incorrect data and if we have tons of animals in here there will be a lot of redundant information. The solution to this is to change this species to a foreign key to another table. Remember that when you create a foreign key it is a child to a parent. The thing you need to know is that the parent has to exist before the child so the child has something to reference. So let's create the parent table. CREATE TABLE Species( ID INT PRIMARY KEY IDENTITY, Species VARCHAR(50) NOT NULL UNIQUE, FriendlyName VARCHAR(50) NOT NULL //NOT UNIQUE because multiple rows could be same category (Ex: Bunny) ); Now, the friendly name will likely have redundant data, so maybe later we can add a table for animal categories or something, but let's not overwhelm ourselves quite yet. Maybe in a few videos. Now that we have created that table, we can recreate the table that references it. The first thing to know when creating a foreign key is that the data type must match. Because the ID column in the species table is of type INT, we should make our Species column in the Animals table also of type INT. Secondly, to make this a foreign key we add REFERENCES Species(ID) to the Species column. DROP TABLE IF EXISTS Animals; CREATE TABLE Animals( ID INT PRIMARY KEY IDENTITY, Name VARCHAR(50) NOT NULL, Species INT NOT NULL REFERENCES Species(ID), ContactEmail VARCHAR(50) NOT NULL UNIQUE ); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 3618 Caleb Curry
Oracle database Training : How to add constraints in Table
 
10:29
Oracle SQL Constraints Oracle Training in Bangladesh Oracle Developer and Database Training in Bangladesh Oracle Training at Dev Net IT Oracle forms Training for details http://www.devnet-it.com
Views: 429 devnetbd devnetit
Add||Constraints||In Table|| In Oracle 11g|| Express Edition|| In Hindi.|Programmer Guys Channel.
 
05:21
_________________________________________________________________ Hello Friends, Welcome To 'Programmer Guys' Channel. _________________________________________________________________ Today In This Video We "Add Constraints Into A Table With Creating A Table In Oracle 11 G EXPRESS EDITION In Hindi". _________________________________________________________________ Thanks For Watching. Please Like, Subscribe And Share. PLEASE SUBSCRIBE :https://goo.gl/KTN53r _________________________________________________________________ These Are The Previous Videos :- For Creating A Table In Oracle 11g :- https://youtu.be/johrcZCNbuY For Adding Data Into A Table In Oracle 11g :- https://youtu.be/L6DPX5k9GRA For Adding Two Numbers In C Language : - https://youtu.be/A01StTyz-fw Making Of Table In C Language :- https://youtu.be/xa4Frci9FJE Print Series Of 1 Using For Loop : - https://youtu.be/AmdeAk2LseM _________________________________________________________________
Views: 56 Programmer Guys

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