Question

如果在php中的sql中插入名称超过5次，如何抛出错误？

$sql = mysql_query("INSERT INTO `transfer`(`t_id`, `agent_id`, `agent_name`, `date`, `name`, `phone`, `email`, `tname`, `tphone`, `temail`, `status`) VALUES (NULL,'$agent_id','$agent_name','$date','$name','$phone','$email','$tname','$tphone','$temail','$cmmnt','$status')");

Answer 1

试试这个

$sql = mysql_query("SELECT * FROM transfer HAVING COUNT(name) > 5");

if (mysql_num_rows($sql) != 0) {

    // There are more than 5 - print an error.
    echo 'Error - More than 5';

}else{

    // No Error - Insert
    $insert_query = "INSERT INTO `transfer`(`t_id`, `agent_id`, `agent_name`, `date`, `name`, `phone`, `email`, `tname`, `tphone`, `temail`, `status`) VALUES (NULL,'$agent_id','$agent_name','$date','$name','$phone','$email','$tname','$tphone','$temail','$cmmnt','$status')";
    $insert_result= $mysqli -> query($insert_query);

}

Answer 2

Please, don't use mysql_* functions in new code. 它们不再被维护，deprecation process已经开始了。看到 red box？了解prepared statements，并使用PDO或 MySQLi - 这个 article会帮你决定哪个。

请参阅上述说明 - 我建议您使用mysqli_函数，因为mysql_函数已被弃用。

$mysqli = new mysqli('localhost', 'username', 'password', 'db');

$query  = "SELECT * FROM transfer HAVING COUNT(name) > 5";
$result = $mysqli -> query($query);
$num    = $result -> num_rows();

if($num != 0){

    // There are more than 5 - print an error.
    echo 'Error - More than 5';

}else{

    // No Error - Insert
    $insert_query = "INSERT INTO `transfer`(`t_id`, `agent_id`, `agent_name`, `date`, `name`, `phone`, `email`, `tname`, `tphone`, `temail`, `status`) VALUES (NULL,'$agent_id','$agent_name','$date','$name','$phone','$email','$tname','$tphone','$temail','$cmmnt','$status')";
    $insert_result= $mysqli -> query($insert_query);

}

Answer 3

注释使用mysqli *而不是mysql * API的重要性非常重要，不应该被忽略，但是因为你已经开始使用mysql *我将继续使用相同的路径...

我相信之前的答案（使用HAVING ...）并未回答您的实际问题。请尝试下面的代码。

$sql = mysql_query("SELECT * FROM transfer WHERE name = '$name'");

if (mysql_num_rows($sql) >= 5) {
    echo "Error - Too many occurrences of $name";
} else {
    $insert_query = "INSERT INTO `transfer`(`t_id`, `agent_id`, `agent_name`, `date`, `name`, `phone`, `email`, `tname`, `tphone`, `temail`, `status`) VALUES (NULL,'$agent_id','$agent_name','$date','$name','$phone','$email','$tname','$tphone','$temail','$cmmnt','$status')";
    $insert_result= $mysqli -> query($insert_query);
}

如果在php的sql中插入名称超过2次，如何抛出错误？

3 个答案: