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If someone knows this it would be great - because I'm still curious how to solve it. However I just remodelled my db structure to eliminate the problem (basically I pulled the several tables into one since each of the table2/table3 tables only has 3 fields) so now I do: table2 ( uid int FK to table1, luid int FK to table1, is_in_table3 boolean, is_in_table4 boolean, ..... ) this just needs a simple select with a join against table1. UC On Saturday 06 November 2004 03:13 pm, Uwe C. Schroeder wrote: > Here's a question for the SQL guru's out there, which I've been trying to > solve for the last couple of hours. There's got to be a solution to this, > but somehow I can't find it. > > Tables: > > table1 ( > uid int PK, > uname varchar(64) > ) > > table2 ( > uid int FK to table1, > xuid int FK to table 1 > ) > > table3 ( > uid int FK to table1, > yuid int FK to table1 > ) > > There might be more tables of the type like table2 and table3, but I'd > already be happy to solve the puzzle with the 3 tables above. > Ok, assume table1 is the master table - in my case a table used for login > authentication (some columns removed above) > table2 and table3 are tables where the uid always references to the uid in > table1. The second "uid" (xuid and yuid in this example) references to > another uid record in table1. The problem is that there may or may not be > entries in table2 (or table3) referencing a specific uid in their second > uid field. > Maybe some data: > > table1: > 1 test1 > 2 test2 > 3 test3 > > table2: > 1 2 > 1 3 > 3 1 > > table3: > 1 2 > 2 3 > 3 2 > > What I want to do in a view is the following resultset: > > uid uname xuid yuid > 1 test1 2 2 > 1 test1 3 > 2 test2 3 > 3 test3 1 > 3 test3 2 > > > So basically I want to know which uid is connected to which uid, one > relationship per row. So xuid and yuid shall be identical if records exist > in both table2 and table3 or the value shall be NULL if a corresponding > record can't be found in either table2 or table3. > > Can anyone here help me out? > > Thanks a lot > > UC - -- Open Source Solutions 4U, LLC 2570 Fleetwood Drive Phone: +1 650 872 2425 San Bruno, CA 94066 Cell: +1 650 302 2405 United States Fax: +1 650 872 2417 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (GNU/Linux) iD8DBQFBjXebjqGXBvRToM4RAq+kAKCyK1bwfRBdVoAvoi0boELr90wSmwCdHUEf p9L9Z1OSHwqvYn+ZnDWSTQw= =Ih7b -----END PGP SIGNATURE----- ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
