Technical Description

Tip: If you are technically inclined, read the following description of how VPME handles using two or more of these special variables in a single view. If you are not so inclined, skip to the next section.

A single view can be used in a form that is involved in Related Forms situations as well as in a form that uses the SQL Find form. In order to be used in all of these situations, the PKValue, ParentPKValue, FIND, RI and GET variables must all be able to be used in the view’s filter (WHERE clause). Using two or more of these variables in a single view requires that the variables not used in any given situation be set to a value that will cause those variables to be “bypassed” when the view is opened or requeried. A variable will be bypassed if its value does not cause any records to be filtered out. For a character field that value would be the null string, so the filter expression would be <field> = ?<variable>, where the variable value has been set to “”. For non-character fields, a range of values must be used, so the filter expression would be <field> >= ?<low value variable> AND <field> <= <high value variable>, where the variable values have been set so that no records are filtered out. We have defined variables to be used in these situations so that variables not used will be bypassed. Code has been added in the appropriate places to make sure that these variables have the correct values for the given situation.

Remote Data Numeric Value Range

The range of values used to bypass as appropriate the numeric parameters in a view may need to vary depending on the remote data database used (SQL Server, Oracle, etc.) in a client-server application. The bypass variable values can be entered on the Data Sources form in the Data Builder.


Creating and Setting Up Remote Views