Question

我是mysql的新手。我有2个mysql表，公司和信息。第一个表有 cid，名称，分类，地址，城市，电话，省，第二个表有 cid，信息dan infodate 。它们是company.cid = info.cid的关系。我用过

SELECT *, MAX(infodate)
FROM company
JOIN info ON company.cid = info.cid
WHERE classification = 'Hotel'
GROUP BY name
ORDER BY MAX(infodate) DESC
LIMIT 0,7

我想在该声明中添加 COUNT ，以便每个公司都有要显示的信息总和。谢谢。

Answer 1

试试这个

SELECT SQL_CALC_FOUND_ROWS *, MAX(infodate)
FROM company
JOIN info ON company.cid = info.cid
WHERE classification = 'Hotel'
GROUP BY name
ORDER BY MAX(infodate) DESC
LIMIT 0,7

然后，要检索计数使用

$total = mysql_fetch_row(mysql_query("SELECT FOUND_ROWS()"));
$total = $total[0];

Answer 2

试试这个

SELECT company.*, COUNT(info.information) 
    FROM company JOIN info ON company.cid = info.cid
    WHERE classification = 'Hotel'
    GROUP BY company.cid
    ORDER BY MAX(info.infodate) DESC
    LIMIT 0,7

Answer 3

如果你这样做会发生什么：

SELECT *, MAX(infodate), COUNT(*) as count

在mysql查询中一起使用MAX和COUNT

3 个答案: