[英]EF Core 3.1 does not allow Contains search on Enum property
我正在嘗試對我的DbSet
中的enum
屬性進行包含搜索,而 EF Core 3.1 會引發以下錯誤
無法翻譯 LINQ 表達式 'DbSet.Where(d => d.Position.ToString().Contains("acc"))'。 以可翻譯的形式重寫查詢,或通過插入對 AsEnumerable()、AsAsyncEnumerable()、ToList() 或 ToListAsync() 的調用顯式切換到客戶端評估
實體:
public class DemoEntity
{
[Key]
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public Position Position { get; set; }
}
枚舉 - 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
}
數據庫上下文:
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>();
}
}
當我按如下方式查詢表時,出現錯誤
try
{
var test = await _context.Demos.Where(x => x.Position.ToString().Contains("acc")).ToListAsync();
}
catch (System.Exception e)
{
//throw;
}
Position 在我的數據庫中屬於NVARCHAR(MAX)
類型。
這是不可能的? 如果是這樣,你能幫我解釋一下嗎?
此問題已記錄在efcore github 存儲庫中,這是現在的解決方法。 enum
屬性需要先轉換成object
string
var test = await _context.Demos.Where(x => ((string) object)x.Position).Contains("acc")).ToListAsync();
希望這可以幫助那里的人。
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