php mysql按行数降序排序

Question

你能帮我吗

$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."'";
 }

我需要按 $sql2 的行数按 id

降序对 $sql 进行排序

Answer 1

如果我理解正确，您希望$sql 的结果按$sql2 为$sql 中的每一行找到的行数排序。这个连接应该这样做，它连接 table2 并按计数排序。

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.