5桌上的Mysql查詢

Question

我搜索了谷歌2小時，沒有運氣，我覺得很簡單。我有4個表，我可以結合在一起的第一個4下面，我有所有表中的所有行。我想弄清楚如何添加1個額外的FullName列，以便所有結果都顯示來自基於b的每行中的table5的FullName，這在所有其他表中都是如此。我希望這對某人有意義。

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個select語句

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 

可能工作等於任何B-？

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