Sales summary report error, DateAdd function not available in MySql about nopcommerce

[coolio986]

Additional information. Version 4.60 uses Date_Add function correctly for MySql

[coolio986]

I have identified the breaking change as commit
9c176a6

[coolio986]

It appears the mapping schema is missing during the data connection creation.
I added

MySqlTools.GetDataProvider(ProviderName.MySqlConnector).MappingSchema

to

NopMappingSchema.cs at GetMappingSchema(string configurationName)

public static MappingSchema GetMappingSchema(string configurationName)
{

    if (Singleton<MappingSchema>.Instance is null)
    {
        Singleton<MappingSchema>.Instance ??= new MappingSchema(configurationName, MySqlTools.GetDataProvider(ProviderName.MySqlConnector).MappingSchema);
        Singleton<MappingSchema>.Instance.AddMetadataReader(new FluentMigratorMetadataReader());
    }

    return Singleton<MappingSchema>.Instance;
}

This is not a very elegant fix, but will suffice until I create a PR

[coolio986]

PR created with a more elegant fix
#7134

[exileDev]

Closed #7132