LinkMaster
LinkMaster lets you specify the
parent table that should drive the contents of a grid. You'll
normally use it together with ChildOrder and RelationalExpr.
Usage
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grdGrid.LinkMaster = cParentAlias
cParentAlias = grdGrid.LinkMaster
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The folks who designed Visual FoxPro think you'll most
often use a grid as the "many" side of a one-to-many
relationship. They're probably right.As a result, grids have a
bunch of properties aimed at making it easy to set up that
situation. Most of these properties are shared with the data
environment's Relation object. LinkMaster isn't one of those—it
belongs only to grids.There are actually two ways to set up a
one-to-many grid. You can do it either by establishing the
correct relation in the data environment or by setting the grid's
properties directly. If you specify a one-to-many relationship
between two cursors in the data environment and then put the
child (many) table in a grid, you'll always see only the child
records that relate to the current parent (one) record (even if
no fields from the parent appear in the form). The alternative
approach is to specify everything at the grid level. When you do
that, LinkMaster contains the alias for the parent table. Set
ChildOrder and RelationalExpr to complete the
relationship.Although LinkMaster can be changed at runtime, we
haven't been able to actually make changing it do anything
useful. Generally, you'll need to change ChildOrder as well, and
that's tricky when you're working in a grid.
Example
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* You'll normally set this one in the Property Sheet, but the
* code would look like:
This.LinkMaster = "OrdItems"
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Copyright © 2002-2018 by Tamar E. Granor,
Ted Roche, Doug Hennig, and Della Martin. Click for license
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