Tuesday, May 22, 2007

What is SQL?

SQL (Structured Query Language) is a computer language used to create, retrieve, update and delete data from relational database management systems. SQL works with database programs like MS SQL Server, MS Access, MSDE, MySQL, DB2, Informix, MS SQL Server, Oracle, Sybase, etc.

SQL Data Manipulation Language (DML)
DML is a syntax for executing queries and DML component of SQL comprises have four basic statements:
SELECT - Retrieve rows from tables
UPDATE - Modify the rows of tables
DELETE - Remove rows from tables
INSERT - Add new rows to tables
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SQL Data Definition Language (DDL)
DDL is used to create and destroy databases, database table and database objects. These commands will primarily be used by database administrators during the setup and removal phases of a database project. DML component of SQL comprises have four basic statements:
CREATE - Creates a new database table
ALTER - Alters / changes a database table
DROP - delete a database table

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