如何從多個表的MySQL

Question

我怎麼能指望所有從2個表，其中...

`approved` == '0' 

行計算行？

Answer 1

你需要做一個聚合上聯：

select sum(subcount) as totalcount 
    from (select count(*) as subcount from table1 where approved = 0 
      union 
      select count(*) as subcount from table2 where approved = 0) 

還有其他的方法，但是這表明你的意圖很清楚，尤其是命名列這樣。

希望這有助於

Answer 2

你會爲每個表做到這一點：

SELECT count(*) FROM table WHERE approved = 0

您可以將其合併成一個查詢而是變得更加複雜。使用子查詢或聯合。

Answer 3

這個答案將幫助您：

$query = "select count(*)+(select count(*) from table1) as totalrows from table2";