Menu
The DBML file is mapping that defines your classes based on your database schema. Yes, it defines your (default) connection string, but it doesn't "configure" your database at all. Linq to Sql uses a database-first approach where you have the database and model your classes after the DB schema.
To create a DBML file, right-click on your project à Go to Add à select New Item à select LINQ to SQL template, give name as “EmployeeDB” and click like as shown below. After adding LINQ to SQL dbml file, that will be as shown below. Here if you observe, we have two sections in the left side section.
To add stored procedures to the O/R Designer dbml file that you added earlier. Click the Sales by Year stored procedure and drag it to the right pane of the designer. Click the Ten Most Expensive Products stored procedure drag it to the right pane of the designer. Save your changes and close the designer.
To install the LINQ to SQL tools, start the Visual Studio installer, choose Modify, then select the Individual Components tab, and then select LINQ to SQL tools under the Code Tools category.
There are three ways to keep the model in sync.
Delete the modified tables from the designer, and drag them back onto the designer surface from the Database Explorer. I have found that, for this to work reliably, you have to:
a. Refresh the database schema in the Database Explorer (right-click, refresh)
b. Save the designer after deleting the tables
c. Save again after dragging the tables back.
Note though that if you have modified any properties (for instance, turning off the child property of an association), this will obviously lose those modifications — you'll have to make them again.
Use SQLMetal to regenerate the schema from your database. I have seen a number of blog posts that show how to script this.
Make changes directly in the Properties pane of the DBML. This works for simple changes, like allowing nulls on a field.
The DBML designer is not installed by default in Visual Studio 2015, 2017 or 2019. You will have to close VS, start the VS installer and modify your installation. The LINQ to SQL tools is the feature you must install. For VS 2017/2019, you can find it under Individual Components > Code Tools.
To update a table in your .dbml-diagram with, for example, added columns, do this:
You could also check out the PLINQO set of code generation templates, based on CodeSmith, which allow you to do a lot of neat things for and with Linq-to-SQL:
Check out the PLINQO site at http://www.plinqo.com and have a look at the intro videos.
The second tool I know of are the Huagati DBML/EDMX tools, which allow update of DBML (Linq-to-SQL) and EDMX (Entity Framework) mapping files, and more (like naming conventions etc.).
Marc
We use a custom written T4 template that dynamically queries the information_schema model for each table in all of our .DBML files, and then overwrites parts of the .DBML file with fresh schema info from the database. I highly recommend implementing a solution like this - it has saved me oodles of time, and unlike deleting and re-adding your tables to your model you get to keep your associations. With this solution, you'll get compile-time errors when your schema changes. You want to make sure that you're using a version control system though, because diffing is really handy. This is a great solution that works well if you're developing with a DB schema first approach. Of course, I can't share my company's code so you're on your own for writing this yourself. But if you know some Linq-to-XML and can go to school on this project, you can get to where you want to be.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With