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VisualizaçõesUnable to cast object of type 'System.String' to type 'System.Byte[]' Error MYSQL NET CORE 3.1
I am implementing Mysql.EntityFramework.Core with NET CORE 3.1. When fetching data it gives the error "Unable to cast object of type 'System.String' to type 'System.Byte []'." Example in:
public new async Task<IList<Rol>> GetAllAsync(Expression<Func<Rol, bool>> condition)
{
var roles = await _dbContext.Rol // <=== HERE Line 26 RolDataStore
.Where(condition).ToListAsync();
return roles;
}
In my configurationDALContext say:
public static void ConfigureDALContext(this IServiceCollection services, string dbConnection)
{
services.AddDbContext<MyDbContext>(options =>
{
options.UseMySQL(dbConnection);
});
}
Model Rol:
public class Rol : IEntity, ISoftDeleteEntity
{
private Guid _id;
public Guid Id
{
get
{
return _id == Guid.Empty ? Guid.NewGuid() : _id;
}
set
{
_id = value;
}
}
public string Nombre { get; set; }
public string Descripcion { get; set; }
public virtual ICollection<Usuario> Usuarios { get; set; }
public DateTime? FechaBaja { get; set; }
}
And the table "Rol":
Exception:
System.InvalidCastException: Unable to cast object of type 'System.String' to type 'System.Byte[]'.
at System.Data.Common.DbDataReader.GetFieldValue[T](Int32 ordinal)
at MySql.Data.MySqlClient.MySqlDataReader.GetFieldValue[T](Int32 ordinal)
at lambda_method(Closure , QueryContext , DbDataReader , ResultContext , Int32[] , ResultCoordinator )
at Microsoft.EntityFrameworkCore.Query.Internal.QueryingEnumerable`1.AsyncEnumerator.MoveNextAsync()
Excepción producida: 'System.InvalidCastException' en System.Private.CoreLib.dll
System.InvalidCastException: Unable to cast object of type 'System.String' to type 'System.Byte[]'.
at System.Data.Common.DbDataReader.GetFieldValue[T](Int32 ordinal)
at MySql.Data.MySqlClient.MySqlDataReader.GetFieldValue[T](Int32 ordinal)
at lambda_method(Closure , QueryContext , DbDataReader , ResultContext , Int32[] , ResultCoordinator )
at Microsoft.EntityFrameworkCore.Query.Internal.QueryingEnumerable`1.AsyncEnumerator.MoveNextAsync()
at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
at GPS.DAL.DataStores.RolDataStore.GetAllAsync(Expression`1 condition) in D:\PROYECTOS\GPSimracing\gpsimracing\api\GPS.DAL\DataStores\RolDataStore.cs:line 26
Can someone help solve this?
2 Respostas
Responde à pergunta0
Finally solved it by installing Nuget "Pomelo.EntityFrameworkCore.MySql" and uninstalling Mysql.Core. This automatically parses it from Char to Guid.
0
The Id column in the database is a string. This is what is returned from the query. But the Id property in the C# side is a Guid. C# Guid values are binary; you have a mismatch there. You need to have Guid.Parse() somewhere, or change the C# Id property to string.
Also, guids are fixed-length, so if that's really what you're doing, varchar(64) seems kind of odd. Depending on how they are formatted, you want one of char(32), char(36), char(38), or char(68).