[英]EF Core 3.1 does not allow Contains search on Enum property
我正在尝试对我的DbSet
中的enum
属性进行包含搜索,而 EF Core 3.1 会引发以下错误
无法翻译 LINQ 表达式 'DbSet.Where(d => d.Position.ToString().Contains("acc"))'。 以可翻译的形式重写查询,或通过插入对 AsEnumerable()、AsAsyncEnumerable()、ToList() 或 ToListAsync() 的调用显式切换到客户端评估
实体:
public class DemoEntity
{
[Key]
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public Position Position { get; set; }
}
枚举 - Position:
public enum Position
{
[Display(Name = "Accountant")]
Accountant,
[Display(Name = "Chief Executive Officer (CEO)")]
ChiefExecutiveOfficer,
[Display(Name = "Integration Specialist")]
IntegrationSpecialist,
[Display(Name = "Junior Technical Author")]
JuniorTechnicalAuthor,
[Display(Name = "Pre Sales Support")]
PreSalesSupport,
[Display(Name = "Sales Assistant")]
SalesAssistant,
[Display(Name = "Senior Javascript Developer")]
SeniorJavascriptDeveloper,
[Display(Name = "Software Engineer")]
SoftwareEngineer
}
数据库上下文:
public class DemoDbContext : DbContext
{
public DemoDbContext(DbContextOptions options)
: base(options) { }
public DbSet<DemoEntity> Demos { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder
.Entity<DemoEntity>()
.Property(e => e.Position)
.HasConversion<string>();
}
}
当我按如下方式查询表时,出现错误
try
{
var test = await _context.Demos.Where(x => x.Position.ToString().Contains("acc")).ToListAsync();
}
catch (System.Exception e)
{
//throw;
}
Position 在我的数据库中属于NVARCHAR(MAX)
类型。
这是不可能的? 如果是这样,你能帮我解释一下吗?
此问题已记录在efcore github 存储库中,这是现在的解决方法。 enum
属性需要先转换成object
string
var test = await _context.Demos.Where(x => ((string) object)x.Position).Contains("acc")).ToListAsync();
希望这可以帮助那里的人。
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