Dropping a Constraint : Constraint « Table « Oracle PL/SQL Tutorial

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Oracle PL/SQL Tutorial » Table » Constraint

6. 10. 5. Dropping a Constraint

Using the DROP CONSTRAINT clause of ALTER TABLE


SQL>

SQL> -- create demo table

SQL> create table myTable(

  2    id           NUMBER(2),

  3    value        NUMBER(6,2)

  4  )

  5  /



Table created.



SQL>

SQL> ALTER TABLE myTable

  2   ADD CONSTRAINT uq UNIQUE (id);



Table altered.



SQL>

SQL> drop table myTable

  2  /



Table dropped.

SQL>

SQL>

6. 10. Constraint
	6. 10. 1.	Adding a Constraint
	6. 10. 2.	Add constaint for a date type column: larger than a certain date
	6. 10. 3.	Adding a 'NOT NULL' Constraint
	6. 10. 4.	The database automatically assigns a name to the constraint
	6. 10. 5.	Dropping a Constraint
	6. 10. 6.	Disabling a Constraint
	6. 10. 7.	Add CASCADE to the end of a DISABLE CONSTRAINT clause
	6. 10. 8.	Enabling a Constraint
	6. 10. 9.	You can also choose to apply a constraint to new data only by specifying ENABLE NOVALIDATE.
	6. 10. 10.	Deferred Constraints
	6. 10. 11.	How to drop a constaint
	6. 10. 12.	Violate a constraint
	6. 10. 13.	Cascade constraints

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