Question

I have a table that consists of some code-cells (for indexing purposes), and one “value” cell (where the data I am interested in lives), similar to the following:

 column:      datatype:

  code1         int
  code2         int
  code3         int
  code4         int
  attributes    varchar(max)

I am checking against some input codes in the stored procedure that adds to this table, and the constraint for adding is that my INPUT codes (@code1, @code2, @code3, @code4) can either equal some value OR they may be null, but are the same as those in some matching row of the table.

What is the best way to say the following statement:

 SET @targetAttributesCell = (SELECT attributes FROM MyTable
                               WHERE (code1 = @code1)
                                 AND (code2 = @code2)
                                 AND (code3 = @code3)
                                 AND (code4 = @code4)); <-- where code1/@code1 'IS NULL' or = '[some integer]'?

Thanks in advance. Please let me know if I need to be more clear.

Answer 1

Here you go:

WHERE ISNULL(Code4,SomeInteger)=SomeInteger

If Code4 is null, it’ll match the integer. If Code4 matches the integer, it’ll match the integer. If Code4 is any other integer, it won’t match.

EDIT

Do you even need this check? Are there NULL values in your table? If so, then the NULL parameters would just match up.