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QUESTION:
When I create only a dbList object on a dbView and the first column of this list is a numeric column I always get the error "Invalid symbol in expression FILE". Can't the dbList handle a numeric first column?
ANSWER:
There is no problem with the dbList regarding a first column being numeric. For example, look at the selectionlist object for customer in the order entry example.
So what's wrong here?
The default behavior of dbList is usage as selectionlist and thus are all properties initialized for usage as selectionlist. The main controlling property for this is the move_value_out_state. If this property is set to TRUE (which is the default) the value of the invoking object is taken on init. Since the view is started from the menu the first menu item (usually labled 'File') is taken and this does not really convert to a numeric value, therefore you get the invalid symbol in expression error.
If you then double click an item in this dbList in the dbView, the move_value_out_state property tells the system to close the view and place the selected value (perhaps customer number 105) at the place where 'File' came from.
So what to do?
If the dbList is used in a dbView (instead of dbModalPanel) you have to set the property move_value_out_state (via the properties dialog in the Studio) to false.
You probably also want to look at the property auto_index_state. Set this property to false if the dbList shows data from a child constrained table and pick the right index for the ordering property of the dbList. The right index is the best index for the relational constraint. If you don't do this, the list can give dramatically bad results since too many records are searched through.
Contributed By:
Vincent Oorsprong
Company: Data Access Worldwide
email: vincent.oorsprong@dataaccess.eu
Web Site: http://www.dataaccess.eu
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