Updating data using linq to sql
Over the last few weeks I've been writing a series of blog posts that cover LINQ to SQL.
LINQ to SQL is a built-in O/RM (object relational mapper) that ships in the .
Obviously this means you would never be able to explicitly null a nullable field.
Trying to have to avoid writing lots of thisfield = thatfield.
Looks like I haven't, which is both good and bad. So, is it possible to make this work where the client has only passed back a single changed value a key reference field?
Db Context _db = new Db Context(); var _product = ( from p in _db. Id == 1 // suppose you getting the first product select p). Say you pass them a serialized record and they pass back an updated serialized record containing only the two fields.
Recently, I have discussed about getting started linq to sql in c#
Finally commit the operation using ‘Submit Changes’ method as before; Just like insert operation, this delete operation example given above will work for .
In my data access layer I have methods for saving and updating records. I previously used Sub Sonic which was great as it had active record and knew that if I loaded a record, changed a few entries and then saved it again, it recognised it as an update and didn't try to save a new entry in the DB. As a result my workflow is like this: Thanks, it's kind of surprising that there's no nicer way of doing it. Thus I have to assume all fields have changed and write the update accordingly.
I've been doing the 'two DB calls' method since starting to use LINQ to SQL but I've always had a nagging feeling I was missing an obviously easier answer. Save Changes(); // this is for EF LINQ to Objects _db. It's tedious but at least I know now I've been doing it the 'proper' way, even though it doesn't seem like doesnt matter what fields have been edited by the user, as long as you pass the model to the Action Result in your controller in HTTPPOST method and call the Save Changes(), the entire records gets updated in the DB.
This will create all the mappings and settings for each table and their entities.
For files the database connection string is defined in the web.config file as: We can use a connection string from the web.config file or we can pass a connection string as a parameter in the constructor of the Data Context class to create an object of the Data Context class.