What is mean by SQL ( structured query language). What are some hidden SQL functions and queries that most people don’t know about it ? How to create a data base in SQL?
What is mean by structured query language (SQL) and how does it work ?
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What is SQL ? SQL stand for structured query language which is a computer language for storing, manipulating and retrieving data stored in a relational data base . It was proposed by IBM developer .
There are different types of commands are used in SQL language such as .
1.DATA DEFINITION LANGUAGE .
2.DATA MANIPULATION LANGUAGE .
3.DATA CONTROL LANGUAGE .
4.TRANSACTION CONTROL LANGUAGE .
5.DATA QUERY LANGUAGE .
There are five types of SQL commands are as follows.
1.Data definition language is used to crate ,drop alter and truncate data .
2.Data manipulation language is used to insert ,update and delete the data .
3. Data control language are used to grant and take back authority from any data base user such as grant and revoke
4.Transaction control language is used to insert , delete and update data only. These operation are automatically committed in data base commands if TCL such as commit ,roll back and save point .
5.Data query language is used to fetch the data from the data base it used only one command like select .
SQL became a standard of the American national standard institute (ANSI) and of the international organisation for standardization (ISO).
–> SQL is used for the following
1. Modifying data base table and index.
2.adding ,updating and deleting rows of data and ,
3.retrieving subsets of information from within relation data base management system .