Which of the following statements are correct?
Explanation
DROP TABLE statement is used to drop an existing table in a database.
DELETE statement is used to delete existing records in a table.
There is no REMOVE statement in SQL.
ALTER TABLE statement is used to modify the table structure - add, delete, or modify columns in an existing table, add and drop various constraints on it.
Theory
  • SQL DROP INDEX, DROP TABLE, and DROP DATABASE

    Indexes, tables, and databases can easily be deleted/removed with the DROP statement.
    Read more: SQL DROP
  • The DROP INDEX Statement

    The DROP INDEX statement is used to delete an index in a table.
    DROP INDEX Syntax for MS Access:
    DROP INDEX index_name ON table_name
    DROP INDEX Syntax for MS SQL Server:
    DROP INDEX table_name.index_name
    DROP INDEX Syntax for DB2/Oracle:
    DROP INDEX index_name
    DROP INDEX Syntax for MySQL:
    ALTER TABLE table_name DROP INDEX index_name
    Read more: SQL DROP
  • The DROP TABLE Statement

    The DROP TABLE statement is used to delete a table.
    DROP TABLE table_name
    Read more: SQL DROP
  • The DROP DATABASE Statement

    The DROP DATABASE statement is used to delete a database.
    DROP DATABASE database_name
    Read more: SQL DROP
  • The TRUNCATE TABLE Statement

    What if we only want to delete the data inside the table, and not the table itself?
    Then, use the TRUNCATE TABLE statement:
    TRUNCATE TABLE table_name
    Read more: SQL DROP
  • SQL DELETE Statement

    The DELETE statement is used to delete records(rows) in a table.

    Syntax

    DELETE FROM table_name
    WHERE some_column=some_value;
    

    Note

    Notice the WHERE clause in the SQL DELETE statement! The WHERE clause specifies which record or records that should be deleted. If you omit the WHERE clause, all records will be deleted!
    Read more.

Follow CodeGalaxy

Mobile Beta

Get it on Google Play
Send Feedback