<< < 26 27 28 29 30 31 32 33 34 35 36 > >>   Sort: Date

Use Variables in SQL Statements in Oracle
Can Variables Be Used in SQL Statements in Oracle? Yes, you can use variables in SQL statements as part of any expressions. The tutorial script provides you some good examples: (Connect to XE with SQL*Plus) CREATE TABLE student (id NUMBER(5) PRIMARY KEY, first_name VARCHAR(80) NOT NULL, last_name VA...
2018-09-24, 571👍, 0💬

Extract Unit Values from a Date and Time in MySQL
How To Extract a Unit Value from a Date and Time in MySQL? If you want to extract a specific date or time unit value out of a date or a time, you can use the EXTRACT(unit FROM expression) function. The tutorial exercise below gives you some good examples: ELECT EXTRACT(DAY FROM NOW()) FROM DUAL; 28 ...
2018-03-13, 571👍, 0💬

"DISABLE TRIGGER" - Disabling Triggers in SQL Server
How To Disable Triggers using "DISABLE TRIGGER" in SQL Server? If want to stop the execution of an existing trigger temporarily, you can use the "DISABLE TRIGGER" statement to disable it. The disabled trigger will be kept in the database. If you want to resume the execution of a disabled trigger, yo...
2016-10-24, 571👍, 0💬

Define a Procedure inside another Procedure in Oracle
How To Define a Procedure inside Another Procedure in Oracle? Define a procedure inside another procedure is supported by PL/SQL. The following tutorial script shows you an example: SQL&gt; CREATE OR REPLACE PROCEDURE HR.DBA_WEEK AS 2 PROCEDURE DBA_TASK (day VARCHAR2) AS 3 BEGIN 4 IF day = 'MOND...
2019-02-18, 570👍, 0💬

Entering Date and Time Values in SQL Server
How To Enter Date and Time values in SQL Server Transact-SQL? Transact-SQL does not support date and time literals. If you want to enter date and time values, you have to use character string literals and rely implicit casting rules to convert them into date and time values. When casting character s...
2017-04-15, 570👍, 0💬

Understanding and Managing Views in SQL Server
Where to find answers to frequently asked questions on Understanding and Managing Views in SQL Server? Here is a list of frequently asked questions and their answers compiled by FYIcenter.com DBA team on Understanding and Managing Views in SQL Server. Clear answers are provided with tutorial exercis...
2016-11-08, 570👍, 0💬

Counting Groups Returned with the GROUP BY Clause in Oracle
How To Count Groups Returned with the GROUP BY Clause in Oracle? If you use the COUNT(*) function on groups returned with the GROUP BY clause, it will count the number of rows within each group, not the number of groups. If you want to count the number of groups, you can put the GROUP BY query into ...
2019-09-16, 569👍, 0💬

Use "WHILE" Loop Statements in Oracle
How To Use "WHILE" Loop Statements in Oracle? If you have a block of codes to be executed repeatedly based a condition, you can use the "WHILE ... LOOP" statement. Here is a sample script on WHILE statements: DECLARE total NUMBER; BEGIN total := 0; WHILE total &lt; 10 LOOP total := total+1; END ...
2018-07-13, 569👍, 0💬

What Are Group Functions in MySQL
What Are Group Functions in MySQL? Group functions are functions applied to a group of rows. Examples of group functions are: COUNT(*) - Returns the number of rows in the group. MIN(exp) - Returns the minimum value of the expression evaluated on each row of the group. MAX(exp) - Returns the maximum ...
2018-01-06, 569👍, 0💬

"ALTER PROCEDURE" - Modifying Existing Stored Procedures in SQL Server
How To Modify an Existing Stored Procedure in SQL Server Transact-SQL? If you find a mistake in an existing stored procedure previously created, you can drop (delete) it and create it again correctly. But dropping a stored procedure may affect other database objects who are depending on this stored ...
2017-01-05, 569👍, 0💬

Creating Triggers for INSERT Statements Only in SQL Server
How To Create a Trigger for INSERT Only in SQL Server? The trigger, dml_message, provided in previous tutorials was defined to handle all 3 types of DML statements, INSERT, UPDATE, and DELETE. If you do not want the trigger to handle all 3 types of DML statements, you can list only 1 or 2 of the sta...
2016-10-24, 569👍, 0💬

"DROP LOGIN" - Deleting a Login Name in SQL Server
How To Delete a Login Name in SQL Server? If you don't want to keep a login name any more, you should delete it by using the "DROP LOGIN" statement as shown in this tutorial example: -- Login with "sa" DROP LOGIN Dba_Login; GO Command(s) completed successfully. -- View login names SELECT name, sid, ...
2016-10-19, 569👍, 0💬

Using Cursors in SQL Server Transact-SQL
Where to find answers to frequently asked questions on Using Cursors in SQL Server Transact-SQL? I want to loop through rows in a result set. Here is a list of frequently asked questions and their answers compiled by FYIcenter.com DBA team on Using Cursors in SQL Server Transact-SQL. Clear explanati...
2016-10-17, 569👍, 0💬

User Role: Group of Privileges in Oracle
What Is a User Role in Oracle? A user role is a group of privileges. Privileges are assigned to users through user roles. You create new roles, grant privileges to the roles, and then grant roles to users.   ⇒Managing Oracle User Accounts, Schema and Privileges ⇒⇒Oracle Database Tutorials
2019-07-30, 568👍, 0💬

Groups of Data Types in MySQL
How Many Groups of Data Types in MySQL? MySQL support 3 groups of data types as listed below: String Data Types - CHAR, NCHAR, VARCHAR, NVARCHAR, BINARY, VARBINARY, TINYBLOB, TINYTEXT, BLOB, TEXT, MEDIUMBLOB, MEDIUMTEXT, LONGBLOB, LONGTEXT, ENUM, SET Numeric Data Types - BIT, TINYINT, BOOLEAN, SMALL...
2018-04-21, 568👍, 0💬

Returning the Second 5 Rows in MySQL
How To Return the Second 5 Rows in MySQL? If you want to display query output in multiple pages with 5 rows per page, and the visitor wants to see the output for the second page, you need to display query output from row 6 to row 10. You can use the "LIMIT startRow maxRows" clause to return only row...
2017-12-21, 568👍, 0💬

DROP INDEX - Removing Existing Indexes in SQL Server
How To Drop Existing Indexes in SQL Server? For some reason, if you want remove an existing index, you can use the DROP INDEX statement with following syntax: CREATE INDEX table_name.index_name The tutorial exercise below shows you how to remove the index "fyi_links_id": USE FyiCenterData; GO SELECT...
2016-11-15, 568👍, 0💬

Rollback the Current Transaction in MySQL
How To Rollback the Current Transaction in MySQL? If you have used some DML statements updated some data objects, you find a problem with those updates, and you don't want those updates to be permanently recorded in the database, you can use the ROLLBACK command. It will remove all the database chan...
2016-10-17, 568👍, 0💬

What Is Commit in MySQL
What Is Commit in MySQL? Commit is a way to terminate a transaction with all database changes to be saved permanently to the database server.   ⇒Database Basics and Terminologies in MySQL ⇒⇒MySQL Database Tutorials
2016-10-16, 568👍, 0💬

Supported Transaction Isolation Levels in Oracle
What Are Transaction Isolation Levels Supported by Oracle in Oracle? Oracle supports two transaction isolation levels: READ COMMITTED (the default option). If the transaction contains DML that requires row locks held by another transaction, then the DML statement waits until the row locks are releas...
2019-08-19, 567👍, 0💬

Create an Index for a Given Table in MySQL
How To Create an Index for a Given Table in MySQL? If you have a table with a lots of rows, and you know that one of the columns will be used often as a search criteria, you can add an index for that column to improve the search performance. To add an index, you can use the "CREATE INDEX" statement ...
2018-02-14, 567👍, 0💬

Deleting an Existing Row from a Table in MySQL
How To Delete an Existing Row from a Table in MySQL? If you want to delete an existing row from a table, you can use the DELETE statement with a WHERE clause to identify that row. Here is good sample of DELETE statements: mysql&gt; INSERT INTO fyi_links (url, id) VALUES ('www.myspace.com', 301);...
2018-01-08, 567👍, 0💬

Filerting out Duplications in Returning Rows in MySQL
How To Filter Out Duplications in Returning Rows in MySQL? If there are duplications in the returning rows, and you want to remove the duplications, you can use the keyword DISTINCT in the SELECT clause. The DISTINCT applies to the combination of all data fields specified in the SELECT clause. The t...
2018-01-06, 567👍, 0💬

Execute SQL Statements in MySQL
How To Execute a SQL Statement in MySQL? You can run any types of SQL statements through the mysql_query() function. It takes the SQL statement as a string and returns different types of data depending on the SQL statement type and execution status: Returning FALSE, if the execution failed. Returnin...
2017-10-23, 567👍, 0💬

<< < 26 27 28 29 30 31 32 33 34 35 36 > >>   Sort: Date