What are the reasons to use SQL Server instead of MySQL with a complex .Net project?

Question

We currently have a 10 year old nasty, spaghetti-code-style SQL Server database that we are soon looking to pretty much re-write from scratch as part of a re-write to a large web application. (The existing application will serve as the functional requirements for the next incarnation of the app) The new version will be developed in .Net, so a large portion of the application stack will be based on Microsoft technologies (Visual Studio will be used IIS will be the application server).

One of the developers on the project has raised the possibility of switching to MySQL instead of SQL Server in order to save on cost for both the licence of the DB server, as well as the tools to design and manipulate the DB (such as the wonderfully free MySQL Workbench).

What are the various pros and cons of using SQL Server vs. MySQL as the database for a complex .Net project? Price is one factor we have identified, both in terms of the DB server licence as well as tools to manipulate the DB, but what other factors come into play?

Answer 1

My pro/con list for MySQL vs. SQL Server for .NET projects would be:

Pros to MySQL:

1. Cost

Pros to SQL Server:

1. Better tooling support, especially for .NET (Entity Framework + other ORM support is MUCH better)
2. Better Visual Studio support
3. Better integration support, especially if you want to do things like Silverlight + RIA, etc.

Answer 2

Have a look at

• DBMS Comparisons: MySQL 5.0 vs. Microsoft SQL Server 2005
• Comparison of Microsoft SQL Server 2005, MySQL 5, and PostgreSQL 8.3
• Microsoft SQL Server vs. MySQL
• MySQL or SQL Server: Look beyond politics and hype when deciding which to use

Answer 3

With SQL Server, you can have better tooling integration ( such as designers) between your entity class and your database schema.

You can just drag a database and drop it in the designer, and viola! All the entities mapping to the tables and their relationships are generated.
_{(source: scottgu.com)}

As for MySQL, obviously licensing cost is an advantage