php - SQL查询未返回计数值

SQl查询运行以从查询中返回总数。

使用PHPmyAdmin运行SQL时，此代码有效

但是在页面上没有显示计数的回声吗？

不知道我是否可以忽略这里的内容。

非常感谢！

$sql2=mysql_query("SELECT count(*)
FROM main_table LEFT JOIN houses ON main_table.housenumber = houses.housenumber AND main_table.streetname = houses.streetname
WHERE main_table.city='1'
group by main_table.city ORDER BY average DESC, houseID DESC, reviewID DESC;");

while($row=mysql_fetch_array($sql2))
{
    $count=$row['count'];
    echo $count;;
}

最佳答案

尝试这个 ....

$sql2=mysql_query("SELECT
      COUNT(*) AS count
    FROM
      main_table
      LEFT JOIN houses
        ON main_table.housenumber = houses.housenumber
        AND main_table.streetname = houses.streetname
    WHERE main_table.city = '1'
    GROUP BY main_table.city
    ORDER BY average DESC,
      houseID DESC,
      reviewID DESC") ;

    while($row=mysql_fetch_array($sql2))
    {
        $count=$row['count'];
        echo $count;
    }

您的查询有误，没有在select作为别名中添加计数，而在使用Alias时在下面添加计数。尝试这个。