Sql updating large number of rows picture dating scan

Rated 3.96/5 based on 864 customer reviews

I sometimes need to do a simple update to ALL rows that resets a status-flag to zero.I don't need to have transactional integrity (but of course if the system crashes, there should be no data corruption.This code, for example, sets the Credit Limit of all Customers with a Cust Credit Status of Premium to 2000: Only the columns corresponding to properties you set in the object created in the Update method's lambda expression will be updated -- any properties you don't set will be left alone.This means that if you have property you want to set to its default, then you must explicitly set that property's value.I understand - and don't like during this specific problem - that PG is a MVCC database and will keep my old versions of the rows before the update alive.

You'll still only make one trip to the database on the call to Save Changes because Entity Framework will bundle up all of the Update statements into a single transmission wrapped inside a transaction.Putting this all together, it means you must know what properties you're going to set .There's no way, at run time, to analyze the return values from your UI, determine what properties your user changed and then construct an object in your lambda expression that sets only those properties.In addition to saving a trip to the database, you also have a method for performing batch deletes.The Delete method itself, by the way, returns an integer result that tells you how many items were deleted (which might be more than one because, after all, there might be multiple customers whose first name is Peter).

Leave a Reply