如何从多个表中计算MySQL的行数

Question

如何计算2个表格中的所有行...

`approved` == '0'

Answer 1

您需要在联盟上进行聚合：

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 )

还有其他方法，但这会非常清楚地显示您的意图，尤其是以这种方式命名列。

希望这有帮助

Answer 2

您可以为每个表执行此操作：

SELECT count(*) FROM table WHERE approved = 0

您可以将其合并为一个查询，但这会变得更复杂。使用子查询或联合。

Answer 3

这个答案可以帮到你：

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