Question

我有一个相当复杂的查询，我用LIKE语句过滤结果。这是查询：

var qsFilter = entities.QueryStatements.Where("it.Statement LIKE @searchTerm", 
    new ObjectParameter("searchTerm", searchTerm));
var qtFilter = entities.QueryTables.Where("it.TableNames LIKE @searchTables", 
    new ObjectParameter("searchTables", searchTerm));

然后：

var tables = from t in entities.TraceLines
    join qs in qsFilter on t.QueryStatementHash equals qs.QueryStatementHash
    join qt in qtFilter on qs.QueryTableHash equals qt.QueryTableHash
    where t.CallTypeId == 64
    orderby t.Sequence
    select new
    {
        Name = qt.TableNames
    };

问题是在最终查询中，它为2个LIKE过滤器生成一个AND子句：

WHERE ([Filter1].[Statement] LIKE @searchTerm) AND 
    ([Extent3].[TableNames] LIKE @searchTables)

如何将其作为 OR 子句？

注意：如果您想知道我在这里使用ESQL的原因，那是因为：How to use SQL 'LIKE' with LINQ to Entities?

Answer 1

虽然我的LinqToEntities经验有限，但我阅读参考资料表明这可能有用：

var joins =
  from t in entities.TraceLines 
  join qs in entities.QueryStatements
    on t.QueryStatementHash equals qs.QueryStatementHash 
  join qt in entities.QueryTables
    on qs.QueryTableHash equals qt.QueryTableHash
  select new {t, qs, qt};

var filtered = joins
  .Where("it.Statement LIKE @searchTerm OR it.TableNames LIKE @searchTables"
    new ObjectParameter("searchTerm", searchTerm)
    new ObjectParameter("searchTables", searchTerm))
  .Where(x => x.t.CallTypeId == 64)

var orderedAndProjected =
  from x in filtered
  order by x.t.Sequence
  select new 
  { 
    Name = qt.TableNames 
  };

我对那些不透明的字符串中的“它”感到困惑。这是一个奇怪的代码选择。

当然，如果你切换到LinqToSql，你可以简单地写一下（但你已经知道了）：

var query = 
  from t in myDC.TraceLines
  from qs in t.QueryStatements
  from qt in qs.QueryTables
  where t.CallTypeId == 64
  where SqlMethods.Like(qs.Statement, searchTerm)
     || SqlMethods.Like(qt.SearchTables, searchTerm)
  order by t.Sequence
  select new
  {
    Name = qt.TableNames
  };

如何在最终表达式中更改2 ESQL where子句的条件？

1 个答案: