SQL DROP

The DROP INDEX  command is used to delete an index in a table.

Syntax:

DROP INDEX table_name.index_name

Drop Table
The DROP Table command is used to delete a table.

 DROP TABLE table_some_name

Drop Database
The Drop Database command is used to delete a database
.

  DROP DATABASE database_some_name

TRUNCATE Table
The TRUNCATE command is used you want delete only data inside the table,not a table.

  TRUNCATE TABLE table_some_name