联盟脚本基于数据集圈

Question

有人可以告诉我，如果我做得好吗？我不太确定，特别是关于第二个图解释的一件事：这个绿色区域是指X和Z的值，还是X或Z？

我在代码中做了一些更正，但似乎我没有正确使用括号。不知道这段代码是否合适

-- 1
/*
// Values stored in Y, that are parts of X and Z
"Y NOT IN (Y EXCEPT (UNION OF X AND Y))"
*/
SELECT Val FROM Y
EXCEPT
SELECT Val FROM X
EXCEPT
SELECT Val FROM Z

-- 2
/*
// Values stored in Y, that are parts of X and Z
"Y NOT IN (Y EXCEPT (UNION OF X AND Y))"
*/
SELECT VAL FROM Y
INTERSECT (
    SELECT Val FROM Y
    EXCEPT
    SELECT Val FROM X
    EXCEPT
    SELECT Val FROM Z
)

-- 3
/*
// Values stored in X and Z. that are not a part of Y
"(UNION OF X & Z) EXCEPT Y"
*/
SELECT VAL FROM X
UNION
SELECT VAL FROM Z 
EXCEPT
SELECT VAL FROM Y

-- 4
/*
// Every value of X, and same values from Y and Z
"(Y NOT IN (Y EXCEPT (UNION OF X AND Y))) UNION X"
*/

SELECT Val FROM X
UNION(
SELECT Val FROM Y
INTERSECT
SELECT Val FROM Z)

Answer 1

我同意1,3和4但是2应该是：

SELECT VAL FROM Y
EXCEPT (
SELECT Val FROM Y
EXCEPT
SELECT Val FROM X
EXCEPT
SELECT Val FROM Z

或者：

(SELECT Val FROM Y
INTERSECT
SELECT Val FROM X)

UNION

(SELECT Val FROM Y
INTERSECT
SELECT Val FROM X)