MySQL What is DDL, DML and DCL?

SQL commands are divided into four subgroups, DDL, DML, DCL, and TCL.

Figure - SQL Commands:

SQL Commands

DDL

DDL is short name of Data Definition Language, which deals with database schemas and descriptions, of how the data should reside in the database.

  • CREATE - to create a database and its objects like (table, index, views, store procedure, function, and triggers)
  • ALTER - alters the structure of the existing database
  • DROP - delete objects from the database
  • TRUNCATE - remove all records from a table, including all spaces allocated for the records are removed
  • COMMENT - add comments to the data dictionary
  • RENAME - rename an object

DML

DML is short name of Data Manipulation Language which deals with data manipulation and includes most common SQL statements such SELECT, INSERT, UPDATE, DELETE, etc., and it is used to store, modify, retrieve, delete and update data in a database.

  • SELECT - retrieve data from a database
  • INSERT - insert data into a table
  • UPDATE - updates existing data within a table
  • DELETE - Delete all records from a database table
  • MERGE - UPSERT operation (insert or update)
  • CALL - call a PL/SQL or Java subprogram
  • EXPLAIN PLAN - interpretation of the data access path
  • LOCK TABLE - concurrency Control

DCL

DCL is short name of Data Control Language which includes commands such as GRANT and mostly concerned with rights, permissions and other controls of the database system.

  • GRANT - allow users access privileges to the database
  • REVOKE - withdraw users access privileges given by using the GRANT command

TCL

TCL is short name of Transaction Control Language which deals with a transaction within a database.

  • COMMIT - commits a Transaction
  • ROLLBACK - rollback a transaction in case of any error occurs
  • SAVEPOINT - to rollback the transaction making points within groups
  • SET TRANSACTION - specify characteristics of the transaction

Courses
Subscribe Updates via Email

Join 49,000+ W3schools lovers and get all the latest tutorials, programs, algorithms in your inbox.