Question

我如何在LINQ中表达以下内容？

select * from table_1 t1
join table_2 t2 on t1.col1 = t2.col1 and t1.col2 <= t2.col2

这是我尝试过的，但我没有得到预期的结果。我想加入 2个表但由于table_1数量不大于或等于table_2 WidgetA数量的List<anObj> table_1 = new List<anObj>(); table_1.Add(new anObj() { Product = "WidgetA", Quantity = 0 }); table_1.Add(new anObj() { Product = "WidgetB", Quantity = 3 }); List<anObj> table_2 = new List<anObj>(); table_2.Add(new anObj() { Product = "WidgetA", Quantity = 1 }); table_2.Add(new anObj() { Product = "WidgetB", Quantity = 1 }); var xList = from t1 in table_1 join t2 in table_2 on t1.Product equals t2.Product where t1.Quantity >= t2.Quantity select new { t1, t2 }; if (xList.Any()) Console.WriteLine("Found"); else Console.WriteLine("None"); //I'm looking for this result.数量我不希望结果中有任何记录（在xList中）。

{{1}}

Answer 1

from t1 in t1datatable
join t2 in t2datatable
        on t1.col1 equals t2.col1
where t1.col2 <= t2.col2
select new
{
    t1,
    t2 
};

Answer 2

最简单的方法是编写以下内容：

var q = from t1 in table_1
        from t2 in table_2.Where(x => t1.col1 == x.col1 && t1.col2 <= x.col2)
        select new { t1, t2 };

（即使它看起来如此，也不会在数据库中创建交叉连接执行计划）

Answer 3

var result = from t1 in db.table_1
             from t2 in db.table_2.Where(x => t1.col1 == x.col1)
                                  .Where(x => t1.col2 <= x.col2)
             select new {t1, t2};

多个linq连接但不同的运算符

3 个答案: