History
1970
SQL was developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Ted Codd in the 1970s.
SQL was the first commercial languages to utilize Edgar F. Codd’s relational model.The model was described in his 1970 paper.
1979
Relational Software, Inc. introduced the first commercially available implementation of SQL, Oracle V2 (Version2) for VAX computers in june.
1986
SQL became a standard language of the American National Standards Institute (ANSI) in 1986. And ANSI and ISO standard groups officially adopted the standard "Database Language SQL" language definition.
1987
SQL became a standard of the International Organization for Standardization (ISO) in 1987.Some Important SQL Command
- DDL- Data Definition Language
- DML- Data Manipulation Language
- DQL- Data Query Language
- DCL- Data Control Language
1. DDL
DDL is Computer Language Which plays a main role in the creation of database language. It is used to specify the database schema and database structure. Through this, both the database schema and database structure are defined as well.
Some commands are also used
- Create : To Create new Database and Table.
- Drop : To use to delete data from table.
- After : It is used to alter the content in the table.
2. DML
DML stand for "Data Manipulation Language". DML is a Computer Programming Language used for inserting, deleting and modifying (updating) data in a database.
Some commands are also used
- Insert : To insert data rows/records in table.
- Update : To update data rows/records in table.
- Delete : To delete records in table.
3. DQL
DQL are used to retrieve data from the database are collectively called DQL.
Some commands are also used
- Select : To used table select in database.
4. DCL
DCL are used to control access to data stored in the database are called DCL.
Some command are also used
- Grant : All user access previleges to database.
- Revoke : In Revoke withdraw user’s access privileges given by using the GRANT command.
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