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ROWID VS ROWNUM IN ORACLE
 
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This Video explains the difference between ROWID and ROWNUM using real project examples. ROWID provides the unique physical address where the row is being stored. ROWNUM indicates the order in which the data was returned from the select query.
Views: 2129 Tech Coach
SQL: pseudo columns (Rowid/Rownum)
 
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In this tutorial, u'll learn the difference between rowid & rownum..
Views: 29856 radhikaravikumar
Oracle Rowid, RowNum and row_number
 
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Oracle Rowid, RowNum and row_number... Explained in detailed...
Views: 5456 CONNECT TO LEARN
HOW TO IDENTIFY AND DELETE DUPLICATE ROWS USING ROWID AND GROUPBY IN ORACLE SQL
 
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This video demonstrates examples on how to find and delete duplicate records from a table. The video gives simple and easy to understand examples on finding duplicate records from a table using group by and having clause and row_number function. It also shows the ways in which duplicates can be deleted very efficiently using the rowid of that record. You can get the code from our website http://oracleplsqlblog.com/FullBlog/FullBlog/21
Views: 8272 Kishan Mashru
ORACLE SQL AND PL/SQL INTERVIEW QUESTION : DIFFERENCE BETWEEN ROWID AND ROWNUM WITH EXAMPLE
 
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In this video tutorial, we discuss the pseudo column rowid and rownum in oracle sql. After watching this video you would be able to understand the basic difference between rowid and a rownum pseudo columns of oracle database. Rowid returns the exact location of the row in the database, hence whenever you retrive a record based on rowid, it is the fastest retrival possible. Whereas for each row returned by a query, the ROWNUM pseudocolumn returns a number indicating the order in which Oracle selects the row from a table or set of joined rows. For more such videos visit out complete list of videos on www.youtube.com/c/kishanmashru Visit or blog www.oracleplsqlblog.com
Views: 1625 Kishan Mashru
Difference between Rowid and Rownum
 
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Difference between Rowid and Rownum If you like this video please share and subscribe channel on youtube for more videos Useful Pl/sql Books http://goo.gl/XMy0tt Watch More... What is Parameterized Cursor in Oracle https://www.youtube.com/watch?v=JMKwHlVi6-A What is autonomous transaction in Oracle. https://www.youtube.com/watch?v=gyvFajpfoWE What are Constraints available in Oracle. https://www.youtube.com/watch?v=WivhdLXQklQ What is Mutation Error and How to avoid mutation. https://www.youtube.com/watch?v=CbWNCyW18Bs 5 Effective way to delete Duplicate rows https://www.youtube.com/watch?v=1wtTtnc87Oc What is Difference between Delete and Truncate https://www.youtube.com/watch?v=7b6wQ3Qumgg
Views: 10498 Ram Gupta
ORACLE SQL INTERVIEW QUESTION : HOW TO SELECT ODD OR EVEN ROWS FROM A TABLE IN ORACLE
 
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This video tutorial answers the frequently asked interview question, how to select only odd or even records in oracle sql, after watching this video you will understand more on the topic and will be able to answer this interview question with a lot of confidence.
Views: 3639 Kishan Mashru
Oracle Partition By clause, Oracle Analytic Functions tutorial
 
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More about analytic functions, visit http://www.learn-with-video-tutorials.com Oracle Analytic Functions and Over By Partition clause enable calculating cumulative and moving aggregates returning multiple rows for each group.
Oracle tutorial : Pseudo columns in Oracle PL SQL (pseudo column)
 
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Oracle tutorial : Pseudo columns in Oracle PL SQL ( pseudocolumn ) oracle tutorial for beginners rownum in oracle This video will show you what is Pseudo columns in Oracle PL SQL. Pseudo columns are likes ROWNUM, ROENUM, ROWID, NEXTVAL,SYSDTAE , USER etc. pseudocolumn examples Oracle tutorial : Pseudo columns in oracle Oracle supports several special-purpose data elements that are not actually contained in a table, but are available for use in SQL statements. Here is a partial list of pseudo-columns in Oracle a)CURRVAL : When using Oracle SEQUENCE values, the pseudo-column CURRVAL returns the current value of the sequence. for example: schema.sequence_name.CURRVAL b)NEXTVAL :When using Oracle SEQUENCE values, the pseudo-column NEXTVAL returns the next value of the sequence and causes the sequence to increment by one. for example: schema.sequence_name.NEXTVAL c)ROWNUM:ROWNUM returns a number indicating the order in which a row was selected from a table. d)ROWID: ROWID returns the rowid (binary address) of a row in a database table. e)USER :This pseudo-column will always contain the Oracle username under which you are connected to the database. f)SYSDATE:This pseudo-column will contain the current date and time. This column is a standard Oracle DATE datatype. The value represents the current time on the server not the client. For more tutorial please visit #techquerypond https://techquerypond.com https://techquerypond.wordpress.com https://twitter.com/techquerypond
Views: 1359 Tech Query Pond
How to Delete the Duplicate Records in oracle
 
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http://oracletemple.blogspot.in/ How to Delete the duplicate records How delete the duplicate rows ? Tips: - Always take extra caution while deleting records. 1. First identify the duplicates using select. 2. Double verify those are actual ‘duplicates’ or not 3. Take backup if necessary 4. Apply commit only if you are sure. -~-~~-~~~-~~-~- Please watch: "difference between delete and truncate" https://www.youtube.com/watch?v=7b6wQ3Qumgg -~-~~-~~~-~~-~- ------------------------------------------------------------------ Below is link for Useful Pl/SQL Books http://goo.gl/XMy0tt ---------------------------------------------------------- Watch More... What is Parameterized Cursor in Oracle https://www.youtube.com/watch?v=JMKwHlVi6-A What is autonomous transaction in Oracle. https://www.youtube.com/watch?v=gyvFajpfoWE What are Constraints available in Oracle. https://www.youtube.com/watch?v=WivhdLXQklQ What is Mutation Error and How to avoid mutation. https://www.youtube.com/watch?v=CbWNCyW18Bs 5 Effective way to delete Duplicate rows https://www.youtube.com/watch?v=1wtTtnc87Oc What is Difference between Delete and Truncate https://www.youtube.com/watch?v=7b6wQ3Qumgg
Views: 21525 Ram Gupta
Oracle sql Interview Question : How to change rows to column
 
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This video tutorial talks about the frequently asked oracle sql interview question of changing rows to the column. Based on the given scenario, we are asked to change the presentation of data in a table with 3 rows and 2 column to 3 columns and 2 rows. Decode Function in oracle https://youtu.be/YUAjPMjqMws Pivot and unpivot in oracle https://youtu.be/6s0DI1YcWIM
Views: 12467 Kishan Mashru
How to Fetch Latest record/row from the Table in Oracle Database
 
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You will learn how to How to Fetch Latest record/row from the Table in Oracle Database. Realtime Scenario: This logic can be implemented to find whether the latest record should be inserted or updated to datawarehouse
ROWID - DBArch Video 32
 
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In this video you will understand what is ROWID in an Oracle Database, where is it stored and what are its components. Our Upcoming Online Course Schedule is available in the url below https://docs.google.com/spreadsheets/d/1qKpKf32Zn_SSvbeDblv2UCjvtHIS1ad2_VXHh2m08yY/edit#gid=0 Reach us at [email protected]
Views: 2731 Ramkumar Swaminathan
How to delete duplicate records from a table in oracle
 
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Let c how to remove duplicates from a table..I have one table here 'student' It has two duplicate records. 3 joe 4 robert These two records has duplicates. So I have to remove them. I can remove them using rowid functionality using one subquery. You can give different column names in GROUP BY clause. to identify the duplicate record. You can give just primary key values also. Duplicate rows are deleted now... Query used in video: delete from student where rowid not in (select min(rowid) from student group by sno,sname); Thanks for watching...:)
Views: 14654 WingsOfTechnology
Using Rownum to find out Nth record from First, Last and within a range in a table.
 
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Using Rownum to find the first nth record and last nth record and in between record in emp table. This is the most frequesntly questions ever asked in interviews.
Views: 3058 Kiranjit Parida
Oracle Interview Questions: Dual table in Oracle
 
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This video is the 2nd video in the video series Oracle Interview questions.It explains dual table in oracle along with the advantages that it offers. Below tutorial explains how you can generate test data in oracle using oracle table and hierarchical queries. https://www.youtube.com/watch?v=Lf8m9lXNPnc&t=25s
Views: 1765 Tech Coach
Hierarchical Queries (Oracle)
 
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Hierarchical Queries in Oracle, Using CONNECT BY PRIOR and START WITH clause. Visual Example using a practical scenario.
Views: 4165 CodeSmith 001
SQL query to find first record and last record in single query
 
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SQL query to find first record and last record in single query
Views: 7641 SQL Guru
How to Remove duplicates from Table using SQL query(Oracle) (rowid)
 
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How to Remove duplicates from Table using SQL query(Oracle) (rowid).. SQL Analysis
Views: 6559 vishwanth suraparaju
SQL Tutorial : How To Delete Duplicate Records in SQL Oracle
 
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SQL Tutorial : How To Delete Duplicate Records in SQL Oracle SQL Tutorial SQL Tutorial for beginners PLSQL Tutorial PLSQL Tutorial for beginners PL/SQL Tutorial PL SQL Tutorial PL SQL Tutorial for beginners PL/SQL Tutorial for beginners Oracle SQL Tutorial
Views: 2558 TechLake
Oracle rownum vs row number
 
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oracle rownum vs ROW_NUMBER
Views: 62 Siva Academy
SELECT statement Processing in an Oracle Database - DBArch  Video 7
 
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You will learn from this video how a SELECT statement is processed in an Oracle Database. You will learn about the a Parse, Execute and Fetch phases in a select statement. Our Upcoming Online Course Schedule is available in the url below https://docs.google.com/spreadsheets/d/1qKpKf32Zn_SSvbeDblv2UCjvtHIS1ad2_VXHh2m08yY/edit#gid=0 Reach us at [email protected]
Views: 20562 Ramkumar Swaminathan
Part 4   Delete duplicate rows in sql
 
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Link for all dot net and sql server video tutorial playlists http://www.youtube.com/user/kudvenkat/playlists Link for slides, code samples and text version of the video http://csharp-video-tutorials.blogspot.com/2014/05/part-4-delete-duplicate-rows-in-sql.html In this video, we will discuss deleting all duplicate rows except one from a sql server table. SQL Script to create Employees table Create table Employees ( ID int, FirstName nvarchar(50), LastName nvarchar(50), Gender nvarchar(50), Salary int ) GO Insert into Employees values (1, 'Mark', 'Hastings', 'Male', 60000) Insert into Employees values (1, 'Mark', 'Hastings', 'Male', 60000) Insert into Employees values (1, 'Mark', 'Hastings', 'Male', 60000) Insert into Employees values (2, 'Mary', 'Lambeth', 'Female', 30000) Insert into Employees values (2, 'Mary', 'Lambeth', 'Female', 30000) Insert into Employees values (3, 'Ben', 'Hoskins', 'Male', 70000) Insert into Employees values (3, 'Ben', 'Hoskins', 'Male', 70000) Insert into Employees values (3, 'Ben', 'Hoskins', 'Male', 70000) The delete query should delete all duplicate rows except one. Here is the SQL query that does the job. PARTITION BY divides the query result set into partitions. WITH EmployeesCTE AS ( SELECT *, ROW_NUMBER()OVER(PARTITION BY ID ORDER BY ID) AS RowNumber FROM Employees ) DELETE FROM EmployeesCTE WHERE RowNumber ] 1
Views: 313801 kudvenkat
Difference between Row Number, Rank and Dense Rank | Oracle SQL Tutorial | Mr.Murali
 
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►For Registration : https://goo.gl/r6kJbB ►Call: +91-8179191999 ► Visit Our Website: http://nareshit.in/ http://nareshit.com/ ► About NareshIT: "Naresh IT is the Best Software Training Institute for Hadoop, Salesforce, AWS, DevOps, Sprak, Data Science, Python, Tableau, RPA ,Java, C#.NET, ASP.NET, Oracle, Testing Tools, Silver light, Linq, SQL Server, Selenium, Android, iPhone, C Language, C++, PHP and Digital Marketing in Hyderabad, Chennai and Vijayawada, India which provides online and classroom training classes" ►For Registration : https://goo.gl/r6kJbB ►Call: India- 8179191999, USA- 404-232-9879 Email: [email protected] ►Our Online Training Features: 1.Training with Real-Time Experts 2.Industry Specific Scenario’s 3.Flexible Timings 4.Soft Copy of Material 5.Share Video's of each and every session. Check The Below Links: ►For Course Reg : https://goo.gl/r6kJbB ► Subscribe to Our Channel: https://goo.gl/q9ozyG ► Circle us on G+: https://plus.google.com/NareshIT ► Like us on Facebook: https://www.facebook.com/NareshIT ► Follow us on Twitter: https://twitter.com/nareshitech ► Visit Our Website: http://nareshit.in/ http://nareshit.com/
Views: 8246 Naresh i Technologies
How to transpose column to row in sql
 
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Hi friends today we will learn how to transpose column data into row of table. #transposecolumntorow Oracle database Unbeatable,Unbreakable Platform..
Views: 14920 Oracle World
Row Number function in SQL Server
 
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sql server row_number example sql server row number by partition sql server row_number over partition by order by In this video we will discuss Row_Number function in SQL Server. This is continuation to Part 108. Please watch Part 108 from SQL Server tutorial before proceeding. Row_Number function Introduced in SQL Server 2005 Returns the sequential number of a row starting at 1 ORDER BY clause is required PARTITION BY clause is optional When the data is partitioned, row number is reset to 1 when the partition changes Syntax : ROW_NUMBER() OVER (ORDER BY Col1, Col2) Row_Number function without PARTITION BY : In this example, data is not partitioned, so ROW_NUMBER will provide a consecutive numbering for all the rows in the table based on the order of rows imposed by the ORDER BY clause. SELECT Name, Gender, Salary, ROW_NUMBER() OVER (ORDER BY Gender) AS RowNumber FROM Employees Please note : If ORDER BY clause is not specified you will get the following error The function 'ROW_NUMBER' must have an OVER clause with ORDER BY Row_Number function with PARTITION BY : In this example, data is partitioned by Gender, so ROW_NUMBER will provide a consecutive numbering only for the rows with in a parttion. When the partition changes the row number is reset to 1. SELECT Name, Gender, Salary, ROW_NUMBER() OVER (PARTITION BY Gender ORDER BY Gender) AS RowNumber FROM Employees Use case for Row_Number function : Deleting all duplicate rows except one from a sql server table. Discussed in detail in Part 4 of SQL Server Interview Questions and Answers video series. Text version of the video http://csharp-video-tutorials.blogspot.com/2015/09/rownumber-function-in-sql-server.html Slides http://csharp-video-tutorials.blogspot.com/2015/09/rownumber-function-in-sql-server_30.html All SQL Server Text Articles http://csharp-video-tutorials.blogspot.com/p/free-sql-server-video-tutorials-for.html All SQL Server Slides http://csharp-video-tutorials.blogspot.com/p/sql-server.html All Dot Net and SQL Server Tutorials in English https://www.youtube.com/user/kudvenkat/playlists?view=1&sort=dd All Dot Net and SQL Server Tutorials in Arabic https://www.youtube.com/c/KudvenkatArabic/playlists
Views: 75209 kudvenkat
Query for nth position of sal  in SQL ?
 
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Hi friends in this video I'll show you how to write a query to find nth position of record or salary from table. Oracle database Unbeatable,Unbreakable Platform..
Views: 1595 Oracle World
Oracle Select Like '% _' With Where Clause 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 use the Like condition with the Where Clause. البحث عن معلومة غير مكتملة 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
Oracle SQL Interview Questions : Delete duplicate records
 
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This is the 1st video of the video series Oracle Interview questions. The video Demonstrates how to delete duplicate records in Oracle. I will cover all the major common questions asked in SQL and PL/SQL interviews as a part of this series. Please do contribute questions that you have come across in any of your interviews
Views: 1977 Tech Coach
Find Duplicate Rows in SQL - Select Statement Tutorial
 
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Find duplicate row values in a field or multiple fields in SQL Server table with this tutorial. Do this for one column, or multiple columns. Uses SQL Server Management Studio for the demonstration.
Views: 40898 Edward Kench
SQL SELECT TOP Clause or LIMIT, OFFSET  and  ROWNUM  Telugu | SQL Telugu Tutorial-vlr training
 
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For all sql videos in Telugu :http://www.vlrtraining.in/sql-training-videos-telugu/ In Telugu: What is the use of ROWNUM in Oracle? What is LIMIT in MySQL? SQL SELECT TOP, LIMIT, ROWNUM SQL TOP, LIMIT or ROWNUM Clause SQL SELECT TOP, LIMIT, ROWNUM SQL Tutorial; SQL SELECT TOP Command Select top in SQL Server SQL SELECT TOP Clause The SELECT TOP clause is used to specify the number of records to return. What is limit in MySQL Limit Data Selections From a MySQL Database. MySQL provides a LIMIT clause that is used to specify the number of records to return. The LIMIT clause makes it easy to code multi page results or pagination with SQL and is very useful for large tables. The SELECT TOP clause is useful on large tables with thousands of records. Returning a large number of records can impact on performance. In English: download sql study material Website: http://www.vlrtrain.in/2016/09/download-sql-files.html Learn SQL sql tutorial for beginners sql commands oracle sql tutorial sql tutorial advanced mysql tutorial sql tutorial video SQL Tutorial, Tutorials SQL
Views: 2621 VLR Training
DISTINCT Clause & UNIQUE Keyword in Oracle | Oracle Tutorials for Beginners
 
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DISTINCT & UNIQUE Keyword in Oracle | Oracle Tutorials for Beginners DISTINCT Keyword in Oracle DISTINCT Clause in Oracle UNIQUE Keyword in Oracle UNIQUE Clause in Oracle Oracle Tutorials for Beginners Oracle Tutorials for Beginners select distinct * sql distinct multiple columns sql distinct count select distinct on one column with multiple columns returned select distinct mysql sql count distinct multiple columns oracle distinct count sql distinct group by sql count distinct two columns select distinct on one column with multiple columns returned select distinct on one column with multiple columns returned oracle sql select unique values from multiple columns select distinct multiple columns mysql select distinct all columns sql count distinct multiple columns group by sql select distinct multiple columns group by select distinct oracle select distinct rows sql select distinct multiple columns select distinct on one column select count distinct select unique mysql how to select unique records in oracle without using distinct sql select distinct values and count of each Oracle Tutorials for Beginners Oracle Tutorials for Beginners Oracle Tutorials for Beginners Oracle Tutorials for Beginners
Views: 397 Oracle PL/SQL World
SQL: Delete Vs Truncate Vs Drop
 
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In this tutorial, you'll learn the difference between delete/drop and truncate. 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: 59613 radhikaravikumar
Merge Statement in Oracle SQL with Example (UPDATE/DELETE or INSERT)
 
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This video demonstrates how to write a Merge Statement in oracle sql, how it is useful in doing a conditional update or delete or both of them when the condition between the target table and source table is evaluated to true, and how we can insert the record into the target table when condition is evaluated to false. The video also shows the use of UPDATE, DELETE and INSERT with Merge, and also the various possible ways to use a Merge statement!!!
Views: 7619 Kishan Mashru
how to use "ROWNUM" in oracle
 
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this video shows how we can display a range of records in ORACLE DATABASE using SQL
Views: 1756 P-Square Technologies
How to Delete Duplicate records(rows) in SQL Server
 
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This video shows to find duplicate records and how to delete Duplicate records in a table.This video explains , best 5 methods to delete duplicate records in table.In this way we can maintain Accuracy and consistence of data data in Database .
Views: 33860 Tech Jago
Базы данных для начинающих. Внутренние индексы SQL таблицы. Таблицы WITHOUT ROWID в SQLite.
 
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Помощь проекту: WMR: R288272666982 WMZ: Z293550531456 Яндекс.Деньги: 410011531129223 Рубрика SQLite на сайте: http://zametkinapolyah.ru/zametki-o-mysql/sqlite/ Текстовая версия: http://zametkinapolyah.ru/zametki-o-mysql/chast-11-7-indeksy-v-bazax-dannyx-sqlite-indeksaciya-tablic-v-sqlite3-algoritm-b-dereva-v-bazax-dannyx.html Паблик блога в ВК: https://vk.com/zametkinapolyah Тематическая группа в ВК: https://vk.com/zametki_bd -- Столбец ROWID или внутренние индексы таблицы в базе данных SQLite -- У каждой таблицы базы данных SQLite по умолчанию есть внутренний индекс, который называет ROWID. Иногда этот индекс совпадает с первичным ключом таблицы PRIMARY KEY, иногда не совпадает, но ROWID есть у каждой таблицы. Если говорить просто и понятно, то ROWID – это дополнительный столбец, который есть у любой таблицы SQLiteи является индексом для данной таблицы. -- Помимо того, что ROWID – это индекс, это еще один способ поддержание целостности данных. Давайте разберемся с индексом ROWID в базах данных SQLite. ROWID–это 64-разрядное число, которое однозначно идентифицирую любую строку в базе данных SQLite. -- Создадим таблицу без индексов и наполним ее данными CREATE TABLE table1(a, b ,c ,d); INSERT INTO table1 (a, b, c , d) VALUES (1, 2, 3, 4); INSERT INTO table1 (a, b, c , d) VALUES (1, 2, 3, 4); INSERT INTO table1 (a, b, c , d) VALUES (1, 2, 3, 4); INSERT INTO table1 (a, b, c , d) VALUES (1, 2, 3, 4); -- посмотрим содержимое таблицы SELECT*FROM table1; -- SQLite не показывает столбец ROWID, если не обращаться к нему по имени, давайте изменим наш запрос SELECT SELECT rowid, a, b, c, d FROM table1; SELECT rowid, a FROM table1; -- Чтобы первичный ключ совпадал с ROWID, нужно создать таблицу следующим образом CREATE TABLE table1(x INTEGER PRIMARY KEY ASC, y, z); CREATE TABLE table2(x INTEGER, y, z, PRIMARY KEY(x ASC)); CREATE TABLE table3(x INTEGER, y, z, PRIMARY KEY(x DESC)); -- Обратите внимание: если столбец PRIMARY KEY объявить как-нибудь по-другому, то значения PRIMARY KEY и ROWID совпадать не будут. -- Таблицы WITHOUT ROWID в базах данных SQLite, таблицы без внутренних индексов -- В SQLite можно создавать таблицы без столбца ROWID, то есть без внутреннего индекса. Такой подход несет незначительные плюсы: иногда это ускоряет выборку данных из базы данных и немного уменьшает объем базы данных. Если вы решили создать таблицу без ROWID в SQLite, то вам необходимо сделать две вещи: во-первых, у таблицы должен быть обязательно первичный ключ, во-вторых, вам необходимо использовать ключевую фразу WITHOUT ROWID. CREATE TABLE IF NOT EXISTS wordcount( word TEXT PRIMARY KEY, cnt INTEGER ) WITHOUT ROWID; INSERT INTO wordcount (word, cnt) VALUES ('word1', 2); INSERT INTO wordcount (word, cnt) VALUES ('word2', 5); INSERT INTO wordcount (word, cnt) VALUES (NULL, 5); CREATE TABLE IF NOT EXISTS wordcount1( word TEXT PRIMARY KEY, cnt INTEGER ); INSERT INTO wordcount1 (word, cnt) VALUES (NULL, 5); -- Теперь у таблицы не будет столбца ROWID. Еще одной особенностью таблиц WITHOUT ROWID является то, что ограничение уровня столбца AUTOINCREMENT работать не будет. Первичный ключ таблицы WITHOUT ROWID ни при каких обстоятельствах не может иметь значение NULL, если вы попробуете добавить NULL в столбец PRIMARY KEY таблицы WITHOUT ROWID, то SQLite выдаст ошибку. Из-за особенностей работы таблиц WITHOUT ROWID, разработчики SQLiteрекомендуют использовать такие таблицы в тех случаях, когда: Вы используете составные первичные ключи или когда первичный ключ не является целым числом, а имеет другой тип данных. Если вам нужно повысить скорость работы таблицы с первичным ключом INTEGER, создавайте таблицу без внутреннего индекса, этим вы ускорите выборку и уменьшите объем базы данных. Если таблицы имеет индекс ROWID и индекс в виде INTEGER PRIMARY KEY, то SQLIte делает перебор двумя циклами: первый цикл идет по столбцу ROWID, второй цикл идет по столбцу INTEGER PRIMARY KEY, хотя значения этих столбцов совпадают. Если в таблицах хранится небольшое количество строк, то таблицы без индекса (WITHOUT ROWID) будут работать несколько быстрее, чем со столбцом ROWID. Если вы проектируете базу данных и хотите ее оптимизировать, то вам не стоит задумываться о том, какие таблицы использовать: ROWID или WITHOUT ROWID, на этапе разработки и проектирования. Тесты лучше всего проводить после того, как база данных будет спроектирована и реализована. Так как никаких отличий между таблицами с ROWID и без нет, за исключением тех, что описаны выше, нет.
SQL with Oracle 10g XE - Using LIKE for Wildcards with SELECT
 
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In this video I use the LIKE command rather than an equals sign to place a condition on my query to allow the use of wildcards within my criteria. When using SQL with Oracle you will need to use the percent sign as the "all characters" wildcard. I perform several queries using the wildcard as describe the results. 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: 4108 Lecture Snippets
Oracle   joins Part -1 by dinesh
 
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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............
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This video gives an example of an inline subquery, a query in the FROM clause of another query. We also see how we might use the rownum option to limit how many rows of output we get. (4 of 6) There is also an "SQL Fundamentals" series. (Search for "databasemec" for tutorials using SQL Server.)
Views: 10422 Jennifer Kreie
Query for employee who hired before 15th of every month in date
 
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Hello friends in SQL language you can write a query for employee who hired before 15th of every month in date easily. Oracle database Unbeatable,Unbreakable Platform..
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Oracle | Sequence & Synonyms by Dinesh
 
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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............
Select Even or Odd Rows From SQL Server Table (myLittleadmin)
 
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Statement to get even or odd rows from a table using myLittleAdmin database for SQL server
Oracle - SQL - Update Statement
 
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Oracle - SQL - Update Statement Watch more Videos at https://www.tutorialspoint.com/videotutorials/index.htm Lecture By: Mr. Anadi Sharma, Tutorials Point India Private Limited.

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