Menu
I have a table structure with partitioned tables, where a few child tables inherit from a common parent. How so I DELETE only from the parent table?
Long story short, I ended up with some data in the parent table, and this should've never happened but now I have to clean up the mess.
937
We cannot delete a parent table that is referenced by a foreign key constraint. We need to either remove the foreign key relationship or drop the child table first. In my example, we need to drop the Employee1 table first because it has a foreign key relationship with the department table.
A foreign key with cascade delete means that if a record in the parent table is deleted, then the corresponding records in the child table will automatically be deleted. This is called a cascade delete in SQL Server.
To empty a table of rows without destroying the table, use DELETE or TRUNCATE . DROP TABLE always removes any indexes, rules, triggers, and constraints that exist for the target table. However, to drop a table that is referenced by a view or a foreign-key constraint of another table, CASCADE must be specified.
You can specify that only parent table matters, simply by using keyword 'ONLY':
DELETE FROM ONLY parent_table_name;
See: http://www.postgresql.org/docs/current/static/sql-delete.html
130
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
