Can we DROP TABLE by foreign key constraint?
Can we DROP TABLE by foreign key constraint?
In SQL Server, you cannot drop a table if it is referenced by a FOREIGN KEY constraint. You have to either drop the child tables before removing the parent table, or remove foreign key constraints.
How do you drop a table that is referenced by a foreign key constraint?
State’ — Drop the foreign key constraint by its name ALTER TABLE dbo….
- Select the tables you want to DROP.
- Select “Save to new query window”.
- Click on the Advanced button.
- Set Script DROP and CREATE to Script DROP.
- Set Script Foreign Keys to True.
- Click OK.
- Click Next -> Next -> Finish.
- View the script and then Execute.
How do I drop a table with constraints?
Procedure
- To explicitly drop unique constraints, use the DROP UNIQUE clause of the ALTER TABLE statement.
- To drop primary key constraints, use the DROP PRIMARY KEY clause of the ALTER TABLE statement.
- To drop (table) check constraints, use the DROP CHECK clause of the ALTER TABLE statement.
How do I drop a foreign key reference in SQL Server?
You can try it if the commands do not work.
- Expand your database view.
- Right Click on Table which has foreign key constraint.
- Right click on the column which has the foreign key reference.
- A list of relationships will appear (if you have one) in a pop up window.
- From there you can delete the foreign key constraint.
How do I delete a foreign key constraint in SQL?
To delete a foreign key constraint
- In Object Explorer, expand the table with the constraint and then expand Keys.
- Right-click the constraint and then click Delete.
- In the Delete Object dialog box, click OK.
How do I delete a foreign key constraint in SQL Server?
Creating a foreign key with DELETE and UPDATE CASCADE rules
- Select the parent table and the primary key column in the parent table.
- In the INSERT and UPDATE specifications, select Cascade for the delete rule.
- Click on Close and save the table in the designer.
How do I delete a foreign key constraint in Oracle?
When you create a foreign key constraint, Oracle default to “on delete restrict” to ensure that a parent rows cannot be deleted while a child row still exists. However, you can also implement on delete cascade to delete all child rows when a parent row is deleted.