ALTER TABLE

ALTER TABLE

1. ADD COLUMN

   • ADD [ COLUMN ] column data_type [ COLLATE collation ] [ column_constraint [ ... ] ]

2. DROP COLUMN

   • DROP [ COLUMN ] [ IF EXISTS ] column [ RESTRICT | CASCADE ]

3. SET TYPE

   • ALTER [ COLUMN ] column [ SET DATA ] TYPE data_type [ COLLATE collation ] [ USING expression ]

4. SET/DROP DEFAULT

   • ALTER [ COLUMN ] column SET DEFAULT expression ALTER [ COLUMN ] column DROP DEFAULT

5. SET/DROP NULL

   • ALTER [ COLUMN ] column { SET | DROP } NOT NULL

6. SET STORAGE

   • ALTER [ COLUMN ] column SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }

7. VALIDATE CONSTRAINT

   • VALIDATE CONSTRAINT constraint_name

8. ADD CONSTRAINT

   • ADD CONSTRAINT constraint_name CHECK condition

9. DROP CONSTRAINT

   • DROP CONSTRAINT [ IF EXISTS ] constraint_name [ RESTRICT | CASCADE ]

10. ADD CONSTRAINT

    • ADD FOREIGN KEY(key_name) REFERENCES table_name(field_name)