PHP MySQL的排序行降數

Question

你能幫助我

$sql="select * from table1 where id='1,2,3,4'"; 
{ 
$sql2="select distinct column1 from table2 where column2='".$row['id']."' and left(date,10) BETWEEN '".$date_from."' AND '".$date_to."'"; 
} 

我需要ID

Answer 1

如果我按行降序爲$ SQL2的數量進行排序$ SQL理解正確的話，你想從$sql結果在$sql通過$sql2每一行中的行數排序。這個連接應該做到這一點，它加入table2，並通過計數降序下達。

SELECT t1.id 
FROM table1 t1 
LEFT JOIN table2 t2 
    ON t1.id=t2.column2 
WHERE id IN (1,2,3,4)      -- should it really be = '1,2,3,4'? 
    AND LEFT(date,10) BETWEEN '2013-01-01' AND '2013-12-31' 
GROUP BY t1.id 
ORDER BY COUNT(DISTINCT t2.column1) DESC 

An SQLfiddle to test with。