I have 4 tables. In first table has appid as primary key and in other three table its foreign key. I want to delete data from all the three in one query. I tried my best but failed. Can anybody help?
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I have 4 tables. In first table has appid as primary key and in other three table its foreign key. I want to delete data from all the three in one query. I tried my best but failed. Can anybody help?
You cannot write a delete statement that references more than one table, you need to write 4 delete statements.
However, if appropriate, you can define the foreign keys on the 3 child tables to “ON DELETE CASCADE”. Then when you delete from the parent table, all associated rows from the 3 child tables are also deleted. This can be useful sometimes, but I would not recommend it as a general practice as it can be dangerous and confusing for developers.