What are the difference between DDL, DML and DCL

Data Definition Language (DDL): ~ statements are used to define the database structure or schema.

1. CREATE - to create objects in the database
2. ALTER - alters the structure of the database
3. DROP - delete objects from the database
4. TRUNCATE - remove all records from a table, including all spaces allocated for the records are removed
5. COMMENT - add comments to the data dictionary
6. RENAME - rename an object

Data Manipulation Language (DML):~ statements are used for managing data within schema objects.

1. SELECT - retrieve data from the a database
2. INSERT - insert data into a table
3. UPDATE - updates existing data within a table
4. DELETE - deletes all records from a table, the space for the records remain
5. MERGE - UPSERT operation (insert or update)
6. CALL - call a PL/SQL or Java subprogram
7. EXPLAIN PLAN - explain access path to data
8. LOCK TABLE - control concurrency

Data Control Language (DCL): ~is used to control the data between different user accounts.

1. GRANT - gives user's access privileges to database
2. REVOKE - withdraw access privileges given with the GRANT command

Transaction Control (TCL): ~ is used to manage the changes made by DML statements. It allows statements to be grouped together into logical transactions.

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