A union is a set of SELECT statements pasted together with a UNION clause. The union returns the combined result sets from both queries. You can use SQLWizard to help you build a union .
SQLWizard allows you to combine up to approximately 33 query results using the UNION operator (the maximum number will depend upon the complexity of your query). You must make certain when writing these queries that the data types of the columns in the SELECT clause match.
To create a union:
When you save, you must save from the SQL view because UNION is not supported by the Query Design window. When you save the query, you will be warned that you will lose your prompted SQL changes.