实体框架为简单比较生成大型查询

Question

我每个类型的层次结构都有一个表。

有一个包含“更新”的表格，并且“Werte”与这些更新直接相关。 “Werte”（值）可以是不同的派生，例如data_bool或data_Int，因此这些“值”有多个表，这是图表：

当我现在做这样的事情时：

IQueryable<Wert> alleWerte = (from w in db.Werte
                              where w.UpdateID == 5
                              select w);

alleWerte.ToList();

执行此操作时，这是由此产生的查询：

SELECT
`UnionAll5`.`C1`, 
CASE WHEN (`UnionAll5`.`C8` = 1) THEN (@gp1)  WHEN (`UnionAll5`.`C9` = 1) THEN (@gp2)  WHEN (`UnionAll5`.`C10` = 1) THEN (@gp3)  WHEN (`UnionAll5`.`C11` = 1) THEN (@gp4)  WHEN (`UnionAll5`.`C12` = 1) THEN (@gp5)  ELSE (@gp6) END AS `C2`, 
`Extent7`.`UpdateID`, 
CASE WHEN (`UnionAll5`.`C8` = 1) THEN (`UnionAll5`.`C2`)  WHEN (`UnionAll5`.`C9` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C10` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C11` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C12` = 1) THEN (NULL) END AS `C3`, 
CASE WHEN (`UnionAll5`.`C8` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C9` = 1) THEN (`UnionAll5`.`C3`)  WHEN (`UnionAll5`.`C10` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C11` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C12` = 1) THEN (NULL) END AS `C4`, 
CASE WHEN (`UnionAll5`.`C8` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C9` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C10` = 1) THEN (`UnionAll5`.`C4`)  WHEN (`UnionAll5`.`C11` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C12` = 1) THEN (NULL) END AS `C5`, 
CASE WHEN (`UnionAll5`.`C8` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C9` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C10` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C11` = 1) THEN (`UnionAll5`.`C5`)  WHEN (`UnionAll5`.`C12` = 1) THEN (NULL) END AS `C6`, 
CASE WHEN (`UnionAll5`.`C8` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C9` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C10` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C11` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C12` = 1) THEN (`UnionAll5`.`C6`) END AS `C7`, 
CASE WHEN (`UnionAll5`.`C8` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C9` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C10` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C11` = 1) THEN (NULL)  WHEN (`UnionAll5`.`C12` = 1) THEN (NULL)  ELSE (`UnionAll5`.`C7`) END AS `C8`, 
`Extent7`.`WertArt_Id`
FROM ((SELECT
`UnionAll4`.`C1`, 
`UnionAll4`.`C2`, 
`UnionAll4`.`C3`, 
`UnionAll4`.`C4`, 
`UnionAll4`.`C5`, 
`UnionAll4`.`C6`, 
`UnionAll4`.`C7`, 
`UnionAll4`.`C8`, 
`UnionAll4`.`C9`, 
`UnionAll4`.`C10`, 
`UnionAll4`.`C11`, 
`UnionAll4`.`C12`
FROM ((SELECT
`UnionAll3`.`C1`, 
`UnionAll3`.`C2`, 
`UnionAll3`.`C3`, 
`UnionAll3`.`C4`, 
`UnionAll3`.`C5`, 
`UnionAll3`.`C6`, 
`UnionAll3`.`C7`, 
`UnionAll3`.`C8`, 
`UnionAll3`.`C9`, 
`UnionAll3`.`C10`, 
`UnionAll3`.`C11`, 
`UnionAll3`.`C12`
FROM ((SELECT
`UnionAll2`.`C1`, 
`UnionAll2`.`C2`, 
`UnionAll2`.`C3`, 
`UnionAll2`.`C4`, 
`UnionAll2`.`C5`, 
`UnionAll2`.`C6`, 
`UnionAll2`.`C7`, 
`UnionAll2`.`C8`, 
`UnionAll2`.`C9`, 
`UnionAll2`.`C10`, 
`UnionAll2`.`C11`, 
`UnionAll2`.`C12`
FROM ((SELECT
`UnionAll1`.`Id` AS `C1`, 
`UnionAll1`.`Data` AS `C2`, 
`UnionAll1`.`C1` AS `C3`, 
`UnionAll1`.`C2` AS `C4`, 
`UnionAll1`.`C3` AS `C5`, 
`UnionAll1`.`C4` AS `C6`, 
`UnionAll1`.`C5` AS `C7`, 
`UnionAll1`.`C6` AS `C8`, 
`UnionAll1`.`C7` AS `C9`, 
`UnionAll1`.`C8` AS `C10`, 
`UnionAll1`.`C9` AS `C11`, 
`UnionAll1`.`C10` AS `C12`
FROM ((SELECT
`Extent1`.`Id`, 
`Extent1`.`Data`, 
NULL AS `C1`, 
NULL AS `C2`, 
NULL AS `C3`, 
NULL AS `C4`, 
NULL AS `C5`, 
1 AS `C6`, 
0 AS `C7`, 
0 AS `C8`, 
0 AS `C9`, 
0 AS `C10`
FROM `Data_Bools` AS `Extent1`) UNION ALL (SELECT
`Extent2`.`Id`, 
NULL AS `C1`, 
NULL AS `C2`, 
NULL AS `C3`, 
NULL AS `C4`, 
NULL AS `C5`, 
`Extent2`.`Data`, 
0 AS `C6`, 
0 AS `C7`, 
0 AS `C8`, 
0 AS `C9`, 
0 AS `C10`
FROM `Data_Strings` AS `Extent2`)) AS `UnionAll1`) UNION ALL (SELECT
`Extent3`.`Id`, 
NULL AS `C1`, 
`Extent3`.`Data`, 
NULL AS `C2`, 
NULL AS `C3`, 
NULL AS `C4`, 
NULL AS `C5`, 
0 AS `C6`, 
1 AS `C7`, 
0 AS `C8`, 
0 AS `C9`, 
0 AS `C10`
FROM `Data_ByteArrays` AS `Extent3`)) AS `UnionAll2`) UNION ALL (SELECT
`Extent4`.`Id`, 
NULL AS `C1`, 
NULL AS `C2`, 
`Extent4`.`Data`, 
NULL AS `C3`, 
NULL AS `C4`, 
NULL AS `C5`, 
0 AS `C6`, 
0 AS `C7`, 
1 AS `C8`, 
0 AS `C9`, 
0 AS `C10`
FROM `Data_DateTimes` AS `Extent4`)) AS `UnionAll3`) UNION ALL (SELECT
`Extent5`.`Id`, 
NULL AS `C1`, 
NULL AS `C2`, 
NULL AS `C3`, 
`Extent5`.`Data`, 
NULL AS `C4`, 
NULL AS `C5`, 
0 AS `C6`, 
0 AS `C7`, 
0 AS `C8`, 
1 AS `C9`, 
0 AS `C10`
FROM `Data_Floats` AS `Extent5`)) AS `UnionAll4`) UNION ALL (SELECT
`Extent6`.`Id`, 
NULL AS `C1`, 
NULL AS `C2`, 
NULL AS `C3`, 
NULL AS `C4`, 
`Extent6`.`Data`, 
NULL AS `C5`, 
0 AS `C6`, 
0 AS `C7`, 
0 AS `C8`, 
0 AS `C9`, 
1 AS `C10`
FROM `Data_Ints` AS `Extent6`)) AS `UnionAll5` INNER JOIN `Werte` AS `Extent7` ON `UnionAll5`.`C1` = `Extent7`.`Id`
 WHERE `Extent7`.`UpdateID` = @p__linq__0

我错了什么？ ：D

说真的可以解释一下吗？数据库中每种类型的表是否真的在做这个？