foreach($states_to_add as $item) {
    $dupesql = "SELECT 
                    COUNT(*) 
                FROM 
                    table 
                WHERE 
                    (   
                        name = '$name' 
                        AND description = '$description' 
                        AND manufacturer = '$manufacturer' 
                        AND city ='$city' 
                        AND price = '$price' 
                        AND enddate = '$end_date'
                    )";

    $duperaw = MysqL_query($dupesql);

    if($duperaw > 0) {
        echo nl2br("$name already exists in $city \n");
    } 
    else {
        $sql = "INSERT INTO table (..... (here go the values to be inserted)
        ....

在运行此检查之前定义每个值,我的结果总是在项目已存在时返回.我倾倒了“dupesql”并将命令复制/粘贴到PHPmyadmin中,后者返回计数0.