User's Guide

Working wih sub queries

Index  Previous  Up  Next

Note: This chapter describes working with Sub-queries used in criteria expressions to limit result dataset (in WHERE, HAVING and SELECT clauses). To find out how to work with sub-queries used as datasources for the main query (i.e. in the FROM and WITH clauses), please refer to the Derived tables chapter.

You may add a sub-query as part of the expression or condition in the Columns Pane while editing text in a cell. To add a sub-query, right click at the text position for a new sub-query and select the Insert Sub-query item from context popup menu or type the "(Select)" text to the Expression column, the "= (Select)" or "In (Select)" text to the Criteria column. Please note that curly brackets are necessary.

Adding a sub-query

To build a newly added sub-query visually, confirm editing by pressing the Enter key. The corresponding tab is created above the Query Building Area and ellipsis button become visible at the right side of the cell (*). By clicking on the ellipsis button you'll be switched to a sub-query tab where you can build it visually in the same way as the main query. If the cell contains more than one sub-query, the drop-down list will appear to select the necessary sub-query.

(*) The ellipsis button appears only in the VCL and ActiveX Editions of Active Query Builder.

You may always get back to the main query and switch to any sub-query or derived table using tabs above the Query Building Area or using the Query Structure Tree.

Getting access to a sub-query

Index  Previous  Up  Next

News

Testimonial

With users expecting better and better interfaces to deal with complex data retrieval, Active Query Builder has allowed me to provide a highly professional, robust environment to both novice users and skilled query writers.

Thanks to all the team involved. Please keep up the good work.
CodeGear - Where Developers Matter