MySQL with EF Core 9: Avoiding Translation Issues
When using EF Core 9 with MySQL in a .NET application, you may encounter SQL translation issues. One of the key problems is that certain queries involving parameterized collections fail to translate.
Note: This article was originally published on my old personal blog. You can also read it there: https://engincanv.github.io/.net/.net9/abp/ef9/2025/01/30/mysql-ef9-in-abp.html
The Problem
When using EF Core 9 with MySQL in a .NET application (if you are using Pomelo.EntityFrameworkCore.MySql NuGet package), you may encounter SQL translation issues. One of the key problems is that certain queries involving parameterized collections fail to translate correctly.
ABP Framework's MySQL provider (Volo.Abp.EntityFrameworkCore.MySQL) relies on
Pomelo.EntityFrameworkCore.MySqlNuGet package. However, as of now, the stable9.0.0version of this package has not been released. (You can follow the upgrade status from #1841, if you want).
The Solution
To workaround this issue, you must explicitly enable the TranslateParameterizedCollectionsToConstants() option in your EF Core configuration. Without this setting, the provider may not correctly translate certain SQL commands.
How to Apply the Fix
Open the module class of the *.EntityFrameworkCore project and configure the AbpDbContextOptions as follows:
//...
public class MyProjectEntityFrameworkCoreModule : AbpModule
{
public override void ConfigureServices(ServiceConfigurationContext context)
{
//...
Configure<AbpDbContextOptions>(options =>
{
options.UseMySQL(builder =>
{
//add the following line 👇
builder.TranslateParameterizedCollectionsToConstants();
});
});
}
}Using the TranslateParameterizedCollectionsToConstants option ensures that parameterized collections are translated into constants, preventing SQL translation errors.
Future Updates
The good news is that once Pomelo.EntityFrameworkCore.MySql 9.0.0 is officially released, this setting will become the default. Actually, it's going to be the default starting from v9.0.0-preview.3.efcore.9.0.0 as announced here.
Until then, applying this temporary solution should allow you to use MySQL with EF Core 9 smoothly.