0

所以我有一个键值对列表，其中键是字符串，值是字符串数组，如下所示：

{
    "filters": [
        {"key": "team", "value": ["3","4","7"]},
        {"key": "placement_type", "value": ["facility"]}
        //{"key": "date", "value": ["2021-01-01"]}
        //{"key": "policy", "value": ["something"]} Number of filters may vary
    ]
}

这个“过滤器”列表可以有多个键值对，具体取决于用户选择的过滤器数量。

所以我需要动态创建的是以下查询：

(builder.Eq("team", "3") | builder.Eq("team", "4") | builder.Eq("team", "7")) & builder.Eq("placement_type", "Facility");

这是我的尝试：

var builder = Builders<ReportDocument>.Filter;

// IF I USE THIS QUERY IT WORKS AS I EXPECT
var hardCodedQuery = (builder.Eq("team", "3") | builder.Eq("team", "4") | builder.Eq("team", "7")) & builder.Eq("placement_type", "Facility");

var dynamicQuery = builder.Empty;
var orFilters = builder.Empty;

foreach (var filter in request.Filters)
{
  if (filter.Value.Length > 1)
  {
     for (int i = 0; i < filter.Value.Length; i++)
     {
        if (i == 0)
        {
          orFilters = builder.Eq(filter.Key, filter.Value[i]); //Had to do this since i have to initiate the variable as builder.Empty and it was adding and EmptyFilterDefinition
        }
        else
        {
          orFilters &= builder.Eq(filter.Key, filter.Value[i]);
        }
      }
      dynamicQuery = builder.Or(orFilters);
   }
   else
   {
      dynamicQuery &= builder.Eq(filter.Key, filter.Value);
   }
}
return await _reportsCollection.Find(dynamicQuery).ToListAsync();

但是一旦我在变量“orFilters”中插入第二个过滤器，操作符“&=”e就变成了MongoDB.Driver。AndFilterDefinition而不是 MongoDB.Driver。或过滤器定义

所以如果有人有好的方法，请分享给大家。我在 stackoverflow 中看到了很多类似我的问题，但都提到只使用 & (And) 运算符来做动态过滤器。但是因为我有一个字符串列表作为值，所以我需要使用 | （或）运算符也是如此。

谢谢

4

1 回答 1

0

您的第一个复合分配与您的预期查询不匹配，在您使用的示例中，OR但在您的代码中您使用的是AND分配

....
if (filter.Value.Length > 1)
  {
     for (int i = 0; i < filter.Value.Length; i++)
     {
        if (i == 0)
        {
          orFilters = builder.Eq(filter.Key, filter.Value[i]); //Had to do this since i have to initiate the variable as builder.Empty and it was adding and EmptyFilterDefinition
        }
        else
        {
          // this line was changed 
          orFilters |= builder.Eq(filter.Key, filter.Value[i]);
        }
      }
      //also when this line run, you are resetting your filter so pay attention to it, should change
      dynamicQuery = builder.Or(orFilters);
   }
   .....
于 2021-09-10T16:17:50.363 回答