Windows Service: EF + MySql without app.config - mysql

Question

At the moment I'm writing a windows service.
I'm already using EntityFramework with MSSQL database which is working perfectly. Now I have to use MySql parallely. But I can't manage to get it running ... I would like to avoid using the app.config and configure EntityFramework via the constructor of my class derived from DbContext.
I have a SqlContext class:
public class SqlContext : DbContext
{
public IDbSet<ServiceauftragSource> ServiceauftragSource { get; set; }
public SqlContext(string connectionString)
: base(connectionString)
{
}
public SqlContext(DbConnection connection)
: base(connection, true)
{
this.Configuration.LazyLoadingEnabled = true;
}
}
In the constructor of my UnitOfWork I try to create my SqlContext:
public SqlUnitOfWork()
{
const string connStr = "server=127.0.0.1;uid=myuser;pwd=mypw;database=mydb;";
MySqlConnection conn = new MySqlConnection(connectionString);
this.Context = new SqlContext(conn);
}
This didn't work. I get the following message when trying to access the database:
Unable to determine the DbProviderFactory type for connection of type 'MySql.Data.MySqlClient.MySqlConnection'. Make sure that the ADO.NET provider is installed or registered in the application config.
Neither did:
public SqlUnitOfWork()
{
this.SetConnectionString();
this.Context = new SqlContext(connectionString);
}
private void SetConnectionString()
{
this.connectionString = "Data Source=" + debugDatabaseServer + ";Initial Catalog=" + debugDatabaseName
+ ";User ID=" + debugDatabaseUsername + ";Password=" + debugDatabasePassword
+ ";Trusted_Connection=False;Persist Security Info=True;";
}
I'm not sure why but I think this is because I haven't told my context its provider (according to other threads on SO it has to be MySql.Data.MySqlClient). But where and how to?
References of the project:
Update
I tried to use my App.config:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</configSections>
<connectionStrings>
<add name="MySqlContext" providerName="MySql.Data.MySqlClient" connectionString="server=localhost;
port=3306;database=***;uid=***;password=***"/>
</connectionStrings>
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />
<providers>
<provider invariantName="MySql.Data.MySqlClient" type="MySql.Data.MySqlClient.MySqlProviderServices,
MySql.Data.Entity.EF6" />
<provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
</providers>
</entityFramework>
</configuration>
When accessing the database I get the following error:
Object reference not set to an instance of an object.
I think this is because my service can't access the app.config after it's being installed. I ensured that app.config is MyService.exe.config after build ...

Answer 1

I've been using MySQL with EF for quite some time pretty flawlessly, what yo need to do is add the following line above your DBContext
[DbConfigurationType(typeof (MySql.Data.Entity.MySqlEFConfiguration))]
so in your case the snippet would look like
[DbConfigurationType(typeof (MySql.Data.Entity.MySqlEFConfiguration))]
public class SqlContext : DbContext
{
public IDbSet<ServiceauftragSource> ServiceauftragSource { get; set; }
public SqlContext(string connectionString)
: base(connectionString)
{
}
public SqlContext(DbConnection connection)
: base(connection, true)
{
this.Configuration.LazyLoadingEnabled = true;
}
}
as for your connection string, i tend to store mine in the web config and then string format for whatever db,server or user i need to create a context for - hope that helps!
NB Im presuming you have your refs to MySQL.data and EF6 as well!