php - PHP - Mysql 语法错误

Question

当我尝试运行该代码时，会出现该错误： 您的 SQL 语法有错误；检查与您的 MySQL 服务器版本相对应的手册，以在第 1 行的 '' 附近使用正确的语法

而且我不知道是什么问题，有人可以帮助我吗？

代码：

<?php include_once("includes/head.php"); ?>
<?php require_once("includes/connect/connect.php"); ?>
<?php require_once("includes/functions.php"); ?>
<?php require_once("includes/jquery.php"); ?>

<?php function friend_request_notification(){
global $db;
global $userid;

$userid = $_SESSION['userid'];

$query_id_see = "SELECT user_id FROM friend_requests WHERE user_id={$userid}";
$result_set3 = mysql_query($query_id_see, $db) or die(mysql_error());

$insert_table = "INSERT INTO friend_requests_notificated (id, user_id, user_id_requester)";
$change_table2 = mysql_query($insert_table) or die(mysql_error());

$select_table = "SELECT id, user_id, user_id_requester FROM friend_requests WHERE user_id={$userid}";
$change_table1 = mysql_query($select_table) or die(mysql_error());


if ($id_requests = mysql_fetch_array($result_set3)){

if ($id_requests2 = mysql_fetch_array($change_table2))
{
}

if ($id_requests1 = mysql_fetch_array($change_table1)) 
{
}



}
else
{
}


}





friend_request_notification();
?>

Answer 1

您的插入查询是错误的。您指定了一堆要使用的字段，但不提供任何值：

INSERT INTO friend_requests_notificated (id, user_id, user_id_requester)
                                                                        ^^^^---??

它应该是

INSERT INTO ... (...) VALUES (x,x,x)
                     ^^^^^^^^^^^^^^^

Answer 2

在插入语句中，您应该给出一些值：

   $insert_table = "INSERT INTO friend_requests_notificated (id, user_id, user_id_requester) 
                     values (...";

Answer 3

INSERT 语句可能会产生语法错误。

基本INSERT 语句的格式为：

插入 [table] 值 ([val1], [val2], ...);