Forum Replies Created

Viewing 15 posts - 1,246 through 1,260 (of 1,413 total)

  • RE: Quickie....

    Imho, best way to count number of occurences of a character in a string is this:

    SELECT LEN('abc@abc@def.com') - LEN(REPLACE('abc@abc@def.com', '@', ''))

    This will tell you that there are two @-signs in...

  • RE: UNIQUE constraint with multiple NULLs

    It is just a unique constraint. SQL Server is correct in handling PKs, just as the standard says PKs must not allow NULLs.

    I also thought about (and tried) ANSI_NULLS ON|OFF,...

  • RE: UNIQUE constraint with multiple NULLs

    Haha, finally someone that find this as interesting as I do.

    Your theory with the hash comparisons sounds reasonable.

    --

    Chris Hedgate @ Apptus Technologies (http://www.apptus.se)

    http://www.sql.nu

  • RE: UNIQUE constraint with multiple NULLs

    Aha! The definition in SQL-99 is this:

    "A unique constraint is satisfied if and only if no two rows in a table

    have the same non-null values in the unique columns"

    So,...

  • RE: UNIQUE constraint with multiple NULLs

    First of all, the "NULL duplicates NULL" (but "NULL never equals NULL") statement was my own words, and maybe badly written. A better way to write it would be (yes...

  • RE: UNIQUE constraint with multiple NULLs

    But it is SQL Server, not Oracle, that is incorrect in the way it handles UNIQUE constraints. SQL-99 states that they should allow multiple NULLs. A NULL is never equal...

  • RE: UNIQUE constraint with multiple NULLs

    Paul, you are absolutely correct, I am just seeking the discussion. And a trigger is the solution I would recommend as well. Now, I may have been unclear, because I...

  • Viewing 15 posts - 1,246 through 1,260 (of 1,413 total)