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  1. #1
    Join Date
    Feb 2004
    Posts
    9

    ERwin. I don't know how I can relation this 2 tables :(

    Table 1
    a+b+c -PK
    Table 2
    a+b+d - PK
    How I can relation this tables with use (a+b)?
    ps
    Sorry for my english

  2. #2
    Join Date
    Feb 2004
    Location
    In front of the computer
    Posts
    15,579
    I would create a parent table with A and B as elements of its primary key. I would create table 1 as a dependant child of the parent with C as part of its PK, and table 2 as a dependant child of the parent with D as part of its Pk.

    -PatP

  3. #3
    Join Date
    Dec 2003
    Location
    Tokyo Japan
    Posts
    26
    yes... do look for the possibility that when designing databases, the physical model doesn't necessary follow from the logical model...

    in some cases, a mapping/relation/linking table (as shown by Pat) is necessary in the physical model [to fulfill the relation requirements in the logical model]

    cheers!

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