5桌上的Mysql查询

Question

我搜索了谷歌2小时，没有运气，我觉得很简单。我有4个表，我可以结合在一起的第一个4下面，我有所有表中的所有行。我想弄清楚如何添加1个额外的FullName列，以便所有结果都显示来自基于b的每行中的table5的FullName，这在所有其他表中都是如此。我希望这对某人有意义。

SELECT a, b, NULL AS Name FROM table1 
union SELECT a, b, NULL AS Name FROM table2 
union SELECT a, b, NULL AS Name FROM table3 
union SELECT a, b, NULL AS Name FROM table4 
union SELECT NULL AS a, b, FullName FROM table5 where 

..... B在以前的4个select语句

Answer 1

SELECT unions.*, tb5.FullName 
FROM (
SELECT a, b FROM table1 
union SELECT a, b FROM table2 
union SELECT a, b FROM table3 
union SELECT a, b FROM table4 
union SELECT a, b FROM table5 
) AS unions 
JOIN table5 AS tb5 ON unions.b = tb5.b 

可能工作等于任何B-？

编辑：更新...