Null predicate

When you specify a Null predicate in the expression editor, you choose a column and specify whether your query must match a NULL or NOT NULL condition in the column.

The expression editor when you have selected the Null predicate is as follows. The fields it contains are:

  • Column. Choose the column on which you are filtering from the drop-down list. You can specify one of the following in identifying a column:
    • Job parameter. A dialog box appears offering you a choice of available job parameters. This allows you to specify the value to be used in the query at run time (the stage you are using the SQL builder from must allow job parameters for this to appear).
    • Expression. An expression editor dialog box appears, allowing you to specify an expression that represents the value to be used in the query.
    • Data flow variable. A dialog box appears offering you a choice of available data flow variables (the stage you are using the SQL builder from must support data flow variables for this to appear)
    • Column. You can directly select a column from one of the tables in the table selection canvas.
  • Is Null/Is Not Null. Choose whether your query will match a NULL or NOT NULL condition in the column.