Linq返回联接中所有表的所有列 [英] Linq return all columns from all tables in the join

问题描述

让我们说我有2个表，它们都包含动态列，我希望在执行左外部联接后从两个表中检索所有列的数据行集合(以后我将其绑定到网格视图).

Lets say I have 2 tables both of them contain dynamic columns and I wish to retrieve a collection of datarow with all the columns from both the tables(later i will bind it to a grid view) after performing left outer join.

样本查询:

var query = from TableA in ds.Tables[0].AsEnumerable()
            join TableB in ds.Tables[1].AsEnumerable() on new { col1 = TableA.Field<Int32>("colA"), col2 = TableA.Field<DateTime>("colB") }
            equals new { col1 = TableB.Field<Int32>("colA"), col2 = TableB.Field<DateTime>("colB") }
            into GJ
            from sub in GJ.DefaultIfEmpty()
            select TableA;

问题: 我想一起选择tableA和tableB.上面的示例查询有效，并且在左外部联接之后填充了tableA的所有列.但是我希望从两个表中检索所有列.请指教.

Problem: I want to select tableA and tableB together. The above sample query works and it populates all columns of tableA after left outer join. But i wish to retrieve all the columns from both the tables. Please advice.

推荐答案

只需将两个部分都选择为匿名类型:

Just select both parts into an anonymous type:

var query = from TableA in ds.Tables[0].AsEnumerable()
            join TableB in [ ...] on [...] equals [...] into GJ
            from sub in GJ.DefaultIfEmpty()
            select new { RowA = TableA, RowB = sub };

结果的每个元素将具有两个属性:RowA是TableA的行，RowB是TableB 的匹配行；如果TableB匹配RowA.

Each element of the result will have two properties: RowA being a row from TableA, and RowB being a matching row from TableB or null if no rows from TableB matches RowA.

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