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iNko
Starting Member
19 Posts |
Posted - 2013-03-31 : 12:08:42
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Here's my database:I am trying to do something like this:"DELETE FROM User WHERE user_name_surname ='user_02'"I dont really know how to explain my problem so ill write a sequence of things that should explain my problem:- i create a new user - user_01- i create a new group - group_01- i assign user_01 to group_01 (User with Membership tables)- i create a new message with user_01 (Message table)- i send this message to group_01 (Group_messages table)Heres where the problem appears:- i create a new user - user_02- i assign this user to already existing group - group_01- i try to delete this user but i cant because group_01 is linked with Group_messages tableSo yeah, can i somehow 'unlink' the user from group? |
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visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
Posted - 2013-04-01 : 00:25:21
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yep you canyou need to first check for use references in membership and Message tables (Message,Single_messages). First delete them from those tables before you delete the user.Another way to deal with it is to create foreignkeys with on delete cascade option so that when you delete a user the reference records will also get deleted from other table. But this is NOT RECOMMENDED as without proper documentation this can be a pain to maintain and support.------------------------------------------------------------------------------------------------------SQL Server MVPhttp://visakhm.blogspot.com/https://www.facebook.com/VmBlogs |
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visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
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iNko
Starting Member
19 Posts |
Posted - 2013-04-01 : 08:49:25
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I think i came up with a simple solution - replacing the relation GROUP_MESSAGES - MEMBERSHIP with GROUP_MESSAGES - GROUP. Now i think everything works how i wanted |
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visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
Posted - 2013-04-01 : 09:51:07
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In any case it should be how i suggested. you've to first delete references before you delete actual record from table.------------------------------------------------------------------------------------------------------SQL Server MVPhttp://visakhm.blogspot.com/https://www.facebook.com/VmBlogs |
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