Linq submitchanges not updating
If our query was like below, then it wouldn’t cause an exception as Phone would never be called.
However, when inserting data we will always get a Sql Exception even if the column was not populated as Linq will try and insert null into the column.
If we change the int to a bigint in the table design then our query would not longer run because Linq couldn’t convert a long to an int.
If we did something like change a nvarchar(50) to a nvarchar(MAX) then this wouldn’t cause a problem as Linq treats them both as a string.
Concurrency control is required to prevent two users from trying to update the same data at the same time. The following are the transactions at the bank branches with concurrency control in place In this example, the account is locked while A is processing the transaction.
It can also prevent one user from seeing out-of-date data while another user is updating the same data. The lock is released only after A’s transaction is finished.
) C:\Drive D\TESTS4WORK\Mvc4Test Planning Schedules\Mvc4Test Planning Schedules\Controllers\Schedule_Other 35 20 Mvc4Test Planning Schedules the entiry framework is designed for statefull applications.
If I removed the phone column from the table and execute the query then I would receive a Sql Exception – Invalid column name ‘Phone’.
Regardless of how many changes you make to your objects, changes are made only to in-memory replicas.
You have made no changes to the actual data in the database.
When the transaction around the submission is completed successfully, the Data Context accepts the changes to the objects by ignoring the change-tracking information.
Dim db As New Northwnd("c:\northwnd.mdf") ' Make changes here. Submit Changes() Catch e As Change Conflict Exception Console.