sql - 连接 3 个表的查询

Question

我希望单个查询产生以下结果..

导致表 1 和表 2 中的记录不在表 3 中。

每个表中有超过 10,000 条记录..所以我正在寻找一个高效的记录。在所有表中 Cono 是主键..

详细的表格。

表 1:-

Cono     

th-123
th-124
th-125

表 2:-

Cono     

th-234
th-245
th-256

表 3:-

Cono     

th-124
th-125
th-256

现在我要有以下记录

结果表:-

Cono     

th-123
th-234
th-245

Answer 1

试试这个

WITH Table1 AS
(
    SELECT 'th-123' CONO UNION
    SELECT 'th-124' UNION
    SELECT 'th-125'
)
,
Table2 AS
(
    SELECT 'th-234' CONO UNION
    SELECT 'th-245' UNION
    SELECT 'th-256'
)
,
Table3 AS
(
    SELECT 'th-124' CONO UNION
    SELECT 'th-125' UNION
    SELECT 'th-256'
)

SELECT CONO
FROM Table1 
WHERE NOT EXISTS
(
    SELECT 1
    FROM Table3
    WHERE TABLE1.CONO = TABLE3.CONO
)

UNION ALL

SELECT CONO
FROM Table2
WHERE NOT EXISTS
(
    SELECT 1
    FROM Table3
    WHERE TABLE2.CONO = TABLE3.CONO
)