What are DDL and DML statements in MySQL?

DDL and DML are different type of SQL queries in MySQL. The full form of DDL and DML is Data Definition language and Data Manipulation Language.

DDL – Data Definition Language:

This are the SQL statements which are most related to Database creating/changing structure. The List of DDL statements are as follow:

  • CREATE – statement is used to create database and other objects
  • ALTER – statement is used to change the database structure
  • DROP – statement is used to delete the database and other objects
  • TRUNCATE – statement  to remove all the records from a table, including all spaces allocated for the records are removed
  • COMMENT – add comments to the data dictionary
  • RENAME – rename is used to rename the objects

DML – Data Manipulation Language:

These are the SQL statements which are related to Database manipulation like fetching, adding, updating data to table. The List of DML statements are as follow:

  • SELECT – statement is used to retrieve/fetch data from the a database
  • INSERT – statement used to insert data into a table
  • UPDATE – statement used to  updates existing data within a table
  • DELETE – deletes all records from a table, the space for the records remain
  • CALL – call a PL/SQL or Java subprogram

DCL – Data Control Language

These are the SQL statements which are related to control the user access to the Database. The List of DCL statements are as follow:

  • GRANT – statement  allows specified privileges to database
  • REVOKE – withdraw access privileges given with the GRANT command

TCL – Transaction Control Language

There are the SQL statements which are related to control transactions. The List of TCL statements are as follow:

  • COMMIT – save work done
  • SAVEPOINT – identify a point in a transaction to which you can later roll back
  • ROLLBACK – restore database to original since the last COMMIT
  • SET TRANSACTION – Change transaction options like isolation level and what rollback segment to use

 

Thank you for reading the article. Please comment if you have any confusion.