What is SQL ?

• What is SQL ?

• Structured Query Language
• Language of relational Databases
• Purpose - manipulate relational data
• Fourth Generation Language (4GL)
• Classified into sub-languages
• DML - Data Manipulation Language
  • SELECT
  • INSERT
  • UPDATE
  • DELETE
• DDL - Data Definition Language (Manipulation of database objects)
  • CREATE TABLE
  • DROP INDEX
  • ALTER SEQUENCE
• DCL - Data Control Language (Data access and permissions)
  • GRANT
  • REVOKE
• TCL - Transaction Control Language (Used to control timing)
  • COMMIT
  • ROLLBACK