Question

我有两个表，操作代码和子操作代码，我需要返回每个代码的所有子代码，只有活动的子代码

public class OperationCode: Entity
{ 
    public guid Id.
    public bool Active{ get; set; }
    public bool Excluded{ get; set; }
    public string Code { get; set; }
    public virtual ICollection<SubOperationCode> SubOperationCode{ get; set; }
}

public class SubOperationCode: Entity
{
    public guid Id.
    public bool Active{ get; set; }
    public bool Excluded{ get; set; }
    public string Code { get; set; }
    public virtual OperationCode OperationCode{ get; set; }
 }

我尝试使用类似的方法，但是没有用

public override OperationCode getById(Guid id)
{
      var result = Db.SubOperationCode.Join(Db.OperationCode,
            sub => sub.Id == id,
            code => code.Id,
            (sub, code) => new { sub, code }).toList();
      return result 
 }

Answer 1

您不需要JOIN-使用导航属性，然后投影到结果列表（在这种情况下为匿名，但可以是模型）。

var operationsWithActiveSubOps = Db.OperationCodes
     .Include(o => o.SubOperationCode)
     .Select(o => new {
          OperationId = o.Id,
          OperationCode = o.Code,
          ActiveSubOperations = o.SubOperationCode.Where(so => so.Active)
     })
     .ToList();

Answer 2

您可以使用以下

public override OperationCode getById(Guid id)
{
  var result = Db.SubOperationCode.Join(Db.OperationCode,
        sub => sub.Id,
        code => code.Id,
        (sub, code) => new { sub, code })
        Where(x => sub.Id == id).toList();
  return result 
}

Answer 3

您可以尝试以下一种方法：

public override OperationCode getById(Guid id)
{
    return Db.OperationCode.Include(o => o.SubOperationCode)
        .FirstOrDefault(o => o.Id == id && o.SubOperationCode.Any(so => so.Active))
}

EF-使用带子句的控制器中的Id参数加入查询

3 个答案: