Updating in linq john mayer cameron diaz dating

Posted by / 29-Jan-2018 21:09

Updating in linq

This seems to be easy to just catch Db Update Concurrency Exception and do nothing, then database naturally wins, and retains its values: However, this way leaves the Db Context, the conflicting entity, and the entity’s tracking information in a corrupted state.

To required EF/Core to check a certain property, just add a System. Microsoft’s Adventure Works sample database does not have such a rowversion column, so create one for the Production.

Then reader Writer2 retries to save the product changes again. As discussed above, to resolve a concurrency conflict, the entity and its tracking information need to be refreshed.

This time, Save Changes should succeed, because there is no conflicts anymore (In this example, there are only 2 database clients reading/writing data concurrently. So the more specific Save Changes overloads can be implemented by applying refresh for each conflict: A Refresh Conflict enumeration has to be defined with 3 members to represent the 3 options discussed above: database wins, client wind, merge client and database..

The following example updates and and deletes the same product concurrently: Inherited from Db Update Exception, Db Update Concurrency Exception has an Entries property.

Entries returns a sequence of Entity Entry instances, representing the conflicting entities’ tracking information.

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The basic idea of resolving concurrency conflicts, is to handle Db Update Concurrency Exception and retry Save Changes: In the above Write overload, if Save Changes throws Db Update Concurrency Exception, the handle Exception function is called.

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