Specify a Column Expression

To specify a column expression:

On the Column Editor tab, specify a name for the column.
Select table-name.column-name from the Expression column. If you added a new column manually, then you must make sure that you specified a table name and a column name.
Click to open the expression builder. The table name and column name are added automatically as the default SQL expression.

The expression is limited to 1024 characters.
On the Fields tab, select columns from the source tables that you have added to the data query.
On the Functions tab, select the functions to apply to the source column.
Enter arithmetic operators and expressions such as CASE statements directly in the SQL expression area.
Click Apply to save the column expression.

Note: If you click the Undo button

after you click Apply, then your last change to the expression is undone. However, because the expression window is closed, you might not notice the undo.