The ShareData method allows you to share a result set between two different DataStores or DataWindow controls. When you share information, you remove the need to retrieve the same data multiple times.
The ShareData method shares data retrieved by one DataWindow control or DataStore (called the primary DataWindow) with another DataWindow control or DataStore (the secondary DataWindow).
When you share data, the result set descriptions for the DataWindow objects must be the same. However, the SELECT statements can be different. For example, you could use the ShareData method to share data between DataWindow objects that have the following SELECT statements (because the result set descriptions are the same):
SELECT dept_id from dept
SELECT dept_id from dept where dept_id = 200
SELECT dept_id from employee
You can also share data between two DataWindow objects where the source of one is a database and the source of the other is external. As long as the lists of columns and their datatypes match, you can share the data.
When you use the ShareData method, the following information is shared:
Primary buffer
Delete buffer
Filter buffer
Sort order
ShareData does not share the formatting characteristics of the DataWindow objects. That means you can use ShareData to apply different presentations to the same result set.
If you perform an operation that affects the result set on either the primary or the secondary DataWindow, the change affects both of the objects sharing the data because the result set is shared. For example, if you call the UpdateData method for the secondary DataWindow, the update operation is applied to the primary DataWindow also.
To turn off the sharing of data, you use the ShareDataOff method. When you call ShareDataOff for a primary DataWindow, any secondary DataWindows are disassociated and no longer contain data. When you call ShareDataOff for a secondary DataWindow, that DataWindow no longer contains data, but the primary DataWindow and other secondary DataWindows are not affected.
In most cases you do not need to turn off sharing, because the sharing of data is turned off automatically when a window is closed and any DataWindow controls (or DataStores) associated with the window are destroyed.
You cannot share data with a DataWindow object that has the Crosstab presentation style.
