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Tuesday, May 31, 2011

SQL TIPS / Work Arounds

SCENARIO 1:

If you have created a View in SQL which is based on a single table – the DML operations you perform on the view are automatically propagated to the base table.
However, when you have joined multiple tables to create a view you will run into below error if you execute a DML statement against the view:

Msg 4405, Level 16, State 1, Line 1
View or function 'ViewName' is not updatable because the modification affects
multiple base tables.

To avoid this error and make a view modifiable you need to create Triggers on the view. These triggers will be used to ‘pass’ the changes to base tables.

You need to create a trigger on a view for all operations you need to perform. For example, if you need to perform INSERT operations on a view you need to create a INSTEAD OF Trigger for ‘passing’ the changes to base tables. If you also need to perform a UPDATE/DELETE operation, you also need to create additional INSTEAD OF Triggers for UPDATE/DELETE.

SCENARIO 2:

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