#ddl and dml commands #dcl command #dcl in sql #sql_dml_ddl_tcl_dcl

What are the differences between DDL, DML and DCL in SQL | developerIndian

1. DDL represent for Data Definition Language. SQL queries like CREATE, ALTER, DROP and RENAME come under this.

   CREATE : to create objects in database
   ALTER : alters the structure of database
   DROP : delete objects from database
   RENAME : rename an objects
   
   Example of creation of table  Data Definition Language

   create table Developer
   (location char(20),
     languae char(15),
     Mark   numeric(12,2));

2. DML represent for Data Manipulation Language. SQL queries like SELECT, INSERT and UPDATE come under this.

   SELECT: retrieve data from the database
   INSERT: insert data into a table
   UPDATE: update existing data within a table
   DELETE: deletes all records from a table, space for the records remain
   
   Example of creation of table Data Manipulation Language
   

   select location
    from developer
    where developer.location= 'india';

3. TCL (Transaction Control Language) :Transaction Control Language commands are used to manage transactions in the database. it is represent commit ,rollback ,Save point 

   COMMIT: Commit command in sql is used to permanently save any transaction
               into the database .
   ROLLBACK: Rollback command restores the database to last committed state.
               It is also used with savepoint command to jump to a savepoint
               in a transaction.
   SAVEPOINT: Savepoint command in sql  is used to temporarily save a
              transaction so that you can rollback to that point 
              whenever necessary.
   Example of creation of table Data Manipulation Language
   mysql> COMMIT; 
   turn off commit 
   mysql> SET autocommit = 0;
   

4. DCL represent  for Data Control Language. SQL queries like GRANT and REVOKE come under this.
   Example of creation of table Data Manipulation Language
   mysql> ROLLBACK;