Question

过去，当我需要在SQL语句的结果中添加一行时，我会写一个这样的语句：

SELECT colA, colB FROM my_table   
UNION  
SELECT 'foo' AS colA, 'bar' as colB;

但是，假设我编写了以下SQL：

SELECT t1.colA, t1.colB, t2.colC FROM my_table t1 INNER JOIN my_other_table t2

当INNER JOIN到另一个像这样的表时，如何将我的额外行添加到my_table？

更新：哇，我只是傻逼。这几乎是回家的时间。我忘记了我的where子句！

SELECT t1.colA, t1.colB, t2.colC
FROM my_table t1
INNER JOIN my_other_table t2
  ON t1.colB = t2.colC

Answer 1

SELECT t1.colA, t1.colB, t2.colC FROM my_table t1 INNER JOIN my_other_table t2
UNION
SELECT 'foo' as colA, 'bar' as colB, 'baz' as colC

Answer 2

SELECT 
    (t1.colA, t1.colB FROM my_table 
     UNION 
     SELECT 'foo' AS colA, 'bar' as colB) as t1 
INNER JOIN 
    my_other_table t2 ON . . .

Answer 3

只需将第二个查询中的mytable替换为(SELECT ...)，即第一个查询（括号内）：

SELECT t1.colA, t1.colB, t2.colC
FROM 
(   SELECT colA, colB
    FROM my_table
  UNION  
    SELECT 'foo' AS colA, 'bar' as colB
) AS t1
INNER JOIN my_other_table t2
  ON t1.colB = t2.colC     
;

如何使用INNER JOIN向SQL查询的结果添加行？

3 个答案: