Updating data linq
Then just use the ‘Submit Changes’ method to commit the changes to database.
Here is a simple code example below which will change a single row:(There is no difference between this and changing multiple row only need to retrieve multiple objects and change them) You will notice an interesting thing here, we didn’t have to use any extra method to tell Data Context object to notify the changes like ‘Insert On Submit’ or ‘Delete On Submit’ methods before .
This will be helpful for debugging purpose and also to learn/know more about original sql syntax.
Here is a simple code snippet that will show how to get the corresponding sql query of a linq to sql operation and print it on console: UDB= new User Data Context(); //simple query var results = from u in TV. User Name == "Admin" select u; //database command object Db Command dc = db.
We don’t have to, because the Data Context object keeps track of all objects it is containing in a time frame(after we retrieving them).
When the ‘Submit Changes’ method called, it simply commits it’s all containing objects’ changes.
Recently, I have discussed about getting started linq to sql in c#
That articles also covered for creating select query for retrieving both single and multiple results.
Imagine that you have a table with columns ID(PK), A, B, C. Change Conflict Exception: Row not found or changed.
Thus, no changes will be reflected to your database.
Sometime, while writing comparatively big linq to sql query, you might be interested to see what kind of resultant sql query is actually generated for a specific kind of operations.
LINQ to SQL tracks your changes and is ready to transmit them back to the database when you call Submit Changes.
rule in the foreign-key constraint in the database, or use your own code to first delete the child objects that prevent the parent object from being deleted. For more information, see How to: Delete Rows From the Database.
Search for updating data linq:
Today, in this tutorial, I will try to give some more examples on other types of database operations, that writes/updates the database.