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lb6688
Starting Member
18 Posts |
 Posted - 2010-08-22 : 15:16:33
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| Parent table (P_1) has two foreign keys on same column (recordno) link to two child tables (c_1, c_2), how would you know, just from the parent table, which recordno/row links to C_1 and which recordno/row link to C_2 |
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russell
Pyro-ma-ni-yak
5072 Posts |
Posted - 2010-08-22 : 17:32:03
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| post DDL |
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visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
Posted - 2010-08-23 : 04:50:09
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| you need to left join from parent to both child tables and based on from which table you get matching values you can determine which record links to which table.------------------------------------------------------------------------------------------------------SQL Server MVPhttp://visakhm.blogspot.com/ |
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lb6688
Starting Member
18 Posts |
Posted - 2010-08-23 : 12:17:00
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| Got it, thanks visakh16. I thought there might be a system variable I can use for that.Thanks again... |
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Lamprey
Master Smack Fu Yak Hacker
4614 Posts |
Posted - 2010-08-23 : 12:55:17
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| Is it possible for a each child table to have the same recordno? |
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visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
Posted - 2010-08-23 : 12:59:31
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| welcome------------------------------------------------------------------------------------------------------SQL Server MVPhttp://visakhm.blogspot.com/ |
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lb6688
Starting Member
18 Posts |
Posted - 2010-08-23 : 22:51:48
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| report back to visakh16, work like a charm. Thanks again.Lamprey, I do not think it's possible (visakh16, correct me if I am wrong), that's what "enforce foreign key constraint" for, isn't it? |
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visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
Posted - 2010-08-24 : 07:32:07
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quote:
Originally posted by lb6688
report back to visakh16, work like a charm. Thanks again.Lamprey, I do not think it's possible (visakh16, correct me if I am wrong), that's what "enforce foreign key constraint" for, isn't it?
Welcome  For second part, its possible. "enforce foreign key constraint" just make sure value put in either of child tables is a valid value in parent table. It doesnt check whether this value was already populated in any of child tables. So there can be chance that you may have same records in both the child tables unless you do check explicitly.------------------------------------------------------------------------------------------------------SQL Server MVPhttp://visakhm.blogspot.com/ |
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Multiple foreign keys