从选择计数 MySQL 语句中获取行数 - Get number of rows from a select count MySQL statement

Get number of rows from a select count MySQL statement

本文关键字：获取语句 MySQL 选择 | 更新日期: 2023-09-27

$How_Many_Manufacturers = "SELECT COUNT(manufacturer), manufacturer
                                   FROM products
                                   WHERE name LIKE '%$new_title%'
                                   GROUP BY manufacturer";

        $result2 = mysql_query($How_Many_Manufacturers, $connection) or die(mysql_error());
$num_rows = mysql_num_rows($result2);
if ($num_rows == 0)
{
    echo "<div id='"noMatches'">No Matches</div>";
                                                   }
else {
                                                   }

if 语句将不起作用。如何更正此脚本？

@Arjan 您的 SQL 语法有错误;请查看与您的 MySQL 服务器版本相对应的手册，了解在第 4 行 -RPM 的"-25,25"附近使用的正确语法

确保在查询中转义 $new_title。

$How_Many_Manufacturers = "SELECT COUNT(manufacturer), manufacturer
                               FROM products
                               WHERE name LIKE '%".mysql_real_escape_string($new_title)."%'
                               GROUP BY manufacturer";

SELECT COUNT 将始终返回一行（即使计数为零）。只需删除 COUNT，或获取行即可查看计数。