Question

我在使用MySQL查询时遇到了一些麻烦。

查询是从两个表中提取的。两个表都包含数据，但我只想要第二个表中的count（*）。

SELECT m.*, (SELECT COUNT(*) FROM cd_members_offers WHERE mo.mo_member_id = m.m_id) as mo_count 
FROM cd_members m, cd_members_offers mo 
/* these are variables and don't always exist */
WHERE (m.m_fname LIKE '%Richie%' OR m.m_lname LIKE '%Richie%' OR m.m_email LIKE '%Richie%')
AND (m.m_signupdate >= 20130807 AND m.m_signupdate <= 20130810)
AND m.m_add_state = 'QLD' 
AND (mo_count >= '2' AND mo_count <= '5') 
/* this is the end of the variables */
AND mo.mo_member_id = m.m_id 
ORDER BY m.m_id ASC

/ *引号* /实际上并不存在于代码中。我只想展示如果输入所有变量，查询可能会如何查看。

我首先遇到了问题，其中会出现许多重复项。我也非常有信心mo_count＆gt; =不是正确的方法。

我还在玩代码并做更多研究，但如果有人能够节省我一些时间，我真的很感激。

Answer 1

试试这个

        SELECT m.*, (SELECT COUNT(*) FROM cd_members_offers mo WHERE mo.mo_member_id = m.m_id) as mo_count 
        FROM cd_members m
        /* these are variables and don't always exist */
        WHERE (m.m_fname LIKE '%Richie%' OR m.m_lname LIKE '%Richie%' OR m.m_email LIKE '%Richie%')
        AND (m.m_signupdate >= 20130807 AND m.m_signupdate <= 20130810)
        AND m.m_add_state = 'QLD' 
        AND (mo_count >= '2' AND mo_count <= '5') 
        /* this is the end of the variables */
        ORDER BY m.m_id ASC

或者可以使用Group By with having子句

        SELECT m.m_id, count(mo.mo_member_id)
        FROM cd_members m,cd_members_offers mo 
        /* these are variables and don't always exist */
        WHERE (m.m_fname LIKE '%Richie%' OR m.m_lname LIKE '%Richie%' OR m.m_email LIKE '%Richie%')
        AND (m.m_signupdate >= 20130807 AND m.m_signupdate <= 20130810)
        AND m.m_add_state = 'QLD' 
        /* this is the end of the variables */
        AND mo.mo_member_id = m.m_id 
        Group by m.m_id
        having count(mo.mo_member_id) between 2 and 5
        ORDER BY m.m_id ASC

Answer 2

很难确定没有看到您的表架构，示例数据等，但您的查询可能看起来像这样

SELECT m.*, COUNT(mo_member_id) mo_count 
  FROM cd_members m LEFT JOIN cd_members_offers mo 
    ON mo.mo_member_id = m.m_id 
 WHERE (m.m_fname LIKE '%Richie%' OR m.m_lname LIKE '%Richie%' OR m.m_email LIKE '%Richie%')
   AND m.m_signupdate >= '2013-08-07' AND m.m_signupdate <= '2013-08-10'
   AND m.m_add_state = 'QLD' 
 GROUP BY m.m_id
HAVING mo_count BETWEEN 0 AND 5

示例输出：

| M_ID | M_FNAME | M_LNAME |          M_EMAIL |                  M_SIGNUPDATE | M_ADD_STATE | MO_COUNT |
--------------------------------------------------------------------------------------------------------
|    1 |  Richie |  Richie |  richie@mail.com | August, 08 2013 00:00:00+0000 |         QLD |        3 |
|    2 | Richie2 | Richie2 | richie2@mail.com | August, 09 2013 00:00:00+0000 |         QLD |        0 |

这是 SQLFiddle 演示

MySql搜索有两个表，一个表仅用于计数

2 个答案: