A connection string is sometimes a bit obscure. Do I need ODBC or OLE DB? When you need one and Google for it, you often find old ones that either don’t work at all anymore, or are not optimal. This article provides you with a couple of ASP.NET to SQL Server connection string examples, and as a bonus for ASP to MySQL too.
Connector/ODBC
MySQL Connector/ODBC C# test script
Whenever you need to test your ASP.NET connection to your MySQL database, using ODBC, you can use the following C# test script. Currently it uses MySQL ODBC 8.0 Unicode Driver, but you can easily change the version used. As a bonus it prints some connection information and it requires an SSL connection to your MySQL database (SslMode=REQUIRED).