Problem getting data without temp table

  • I have a table (TFI) that contains the column names of another table (T1).  I want to do a SELECT joining these tables and getting the value in the referenced field in T1.

    Does anyone know of a way to get the value of the column in another table without building a temporary table?

    Example:

    T1 - has two columns T1_ID and T1_Col

    values are (1,field1,2,field2,3,field3)

    F1 - has four columns (F1_ID,field1,field2,field3)

    values are (1,'A','B','C',2,'D','E','F')

    I want to get the values in F1 by referencing the T1_Col name.

    Let me know if this is not clear.

     

    Thanks!

     

  • Hi,

    Are you Saying:

    t1_IDColumnName
    1Field1
    2Field2
    3Field3

    and

    f1_IDField1Field2Field3
    1abc
    2def
    3xyz

    If That is the case....What do you want to do with them?


    Kindest Regards,

    Tal Mcmahon

  • I want to be able to do a SELECT on T1 and get the value of the field in F1 back.  Of course I have simplified the problem I am having to the basics.

    Hope that makes since and you can help.

  • Is this the sort of thing?

    declare @col varchar(10), @SQLText varchar(255)

    select @col = col

    from t1

    where id = 2

    set @SQLText = 'select ' + @col + ' from f1'

    exec (@SQLText)

    If you haven't even tried to resolve your issue, please don't expect the hard-working volunteers here to waste their time providing links to answers which you could easily have found yourself.

  • It's not clear, but maybe you're asking for a simple join?

    select T1_ID, T1_COL, field1, field2, field3

    from T1 inner join F1 on (T1.T1_ID = F1.F1_ID)

  • /* creating the date (if not available) */

    IF OBJECT_ID('tempdb..#T1') IS NOT NULL DROP TABLE #T1

    CREATE TABLE #T1 (T1_ID INT, T1_Col VARCHAR(256))

    INSERT INTO #T1 SELECT 1, 'field1'

    INSERT INTO #T1 SELECT 2, 'field2'

    SELECT * FROM #T1

    IF OBJECT_ID('tempdb..#F1') IS NOT NULL DROP TABLE #F1

    CREATE TABLE #F1 (F1_ID INT, field1 VARCHAR(256), field2 VARCHAR(256), field3 VARCHAR(256))

    INSERT INTO #F1 SELECT 1, 'A','B','C'

    INSERT INTO #F1 SELECT 2, 'D','E','F'

    INSERT INTO #F1 SELECT 3, 'x','y','z'

    SELECT * FROM #F1

    /* finished creating the data */

    DECLARE @a VARCHAR(8000), @b-2 VARCHAR(8000)

    SELECT @a = ' SELECT ', @b-2 = ' FROM #F1'

    /* creates the list of columns */

    SELECT @a = @a + ISNULL(T1_Col + ',', '')

    FROM #T1 cols

    /* removes the last ',' */

    SELECT @a = REPLACE (@a + ',', ',,', '')

    EXEC (@a + @b-2)


    Daniel

  • Maybe i'm missing something......

    Does:

    SELECT F1.F1_ID, F1.field1, F1.field2,F1.field3

    FROM F1, T1

    WHERE T1.Feild1 = F1.Feild1

    AND T1.Feild2 = F1.Feild2

    AND T1.Feild1 = 'Whatever it is you want'

    Not cover what you are looking for?

    Steve

    We need men who can dream of things that never were.

  • Phil you have the general idea but the id = 2 is too simple.  I want to to do this for all records and update a field in one pass.  I don't think this can be done.  Maybe I simplified my problem too much for the posting because it is a much bigger problem than most people are giving solutions for.  I tried to make it a simple as possible.  I think I am going to have to either use a temp table or a cursor.  Thanks for trying.

Viewing 8 posts - 1 through 7 (of 7 total)

You must be logged in to reply to this topic. Login to reply