entity framework 4 - which is the difference betwwen this two ways to refresh the dbContext? -

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i using ef 4.4 , update many entities, other user can modified many of entities first user modified. concurrency exception. other case first user tries add many new registers , other user added of them meanwhile. have exception exists of registers (unique constraint).

i ensure first user finish operation add registers no exists yet (add entities except entities added second user).

to that, need update entities in dbcontext see there @ least 2 options.

first, in catch when capture update exception, can do:

ex.entries.single().reload();

the second option is:

mycontext.entry<mytable>(instance).reload();

i guess second option refreshes entity use parameter, if problem need refresh many entities, how can that?

what first option, single().reload?

when do

ex.entries.single().reload();

you sure offending entity refreshed. taking 1 , (single) entity dbupdateconcurrencyexception.entries not saved database (in case of concurrency exception one).

when do

mycontext.entry(instance).reload();

you not sure refresh right entity unless know 1 entity had changes before savechanges called. if save entity child entities 1 of them can cause concurrency problem.


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