Friday, February 24, 2012

Delete rows in relational database

Hi,
I have a relational database. Pretty simple I created it just for learning from it.

I have two tables "Categories" and "Subcategories".

I have a field called "CategoryID" in the Subcategories table that is a foreign key , and is related to the first table (categories).

Now what I want to do is, when I delete a row in the "Categories" table, I also want to delete the related rows in the other table (if any exist) at the same time.

I hope I explained the problem accurately, if you need any details please let me know

Thanks in advace,
WassimHi,

You need to delete the rows from the subcategories table first and then delete the corresponding rows from the categories table.

It should be pretty easy as the CategoryID should be in SubCategories table and that the field you need to use to delete rows from the subcategories table.

I hope this helps.

Aash.|||Look at the CASCADE DELETE capability defined when you set the relationship between the two tables. This is inherent and designed to provide for integrity as part of the db structure

Jim|||

Quote:

Originally Posted by Jim Doherty

Look at the CASCADE DELETE capability defined when you set the relationship between the two tables. This is inherent and designed to provide for integrity as part of the db structure

Jim


Hi Jim,

yes that's what I did exactly. That's amazing. if you force your tables to "Cascade Delete", and you delete a row in a parent table, all the rows in the childs tables will also be removed :)

Thanks|||

Quote:

Originally Posted by Tea Maker

Hi Jim,

yes that's what I did exactly. That's amazing. if you force your tables to "Cascade Delete", and you delete a row in a parent table, all the rows in the childs tables will also be removed :)

Thanks


You got it.... glad it helped you

Jim

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