为什么这个PHP/mySQL查询会给我一个错误？

我正在生成查询的第一部分，如下所示：

while ($all_products = $db->fetch_array($all_prods))
        {
            $filter_string .= 'AND product_id !=';
            $filter_string .= $all_products['item_id'];
            $filter_string .= ' ';
}

$sql_more_items = $db->query("SELECT * FROM db_products 
WHERE owner_id='" . $user_id . "' AND active=1 '" . $filter_string . "' 
ORDER BY RAND() LIMIT 10");

$queryString = "SELECT * FROM db_products WHERE owner_id='$user_id'"
." AND active=1 "                       //Note these 
. $filter_string                        //are separated 
. "ORDER BY RAND() LIMIT 10 ";          //into individual lines

$sql_more_items = $db->query($queryString);

然后第二部分是这样的：

while ($all_products = $db->fetch_array($all_prods))
        {
            $filter_string .= 'AND product_id !=';
            $filter_string .= $all_products['item_id'];
            $filter_string .= ' ';
}

$sql_more_items = $db->query("SELECT * FROM db_products 
WHERE owner_id='" . $user_id . "' AND active=1 '" . $filter_string . "' 
ORDER BY RAND() LIMIT 10");

$queryString = "SELECT * FROM db_products WHERE owner_id='$user_id'"
." AND active=1 "                       //Note these 
. $filter_string                        //are separated 
. "ORDER BY RAND() LIMIT 10 ";          //into individual lines

$sql_more_items = $db->query($queryString);

但是它给了我一个mySQL语法错误，

$filter_string

部分奇怪地在字符串前后添加了两次

'

，因此它的运行方式如下：

while ($all_products = $db->fetch_array($all_prods))
        {
            $filter_string .= 'AND product_id !=';
            $filter_string .= $all_products['item_id'];
            $filter_string .= ' ';
}

$sql_more_items = $db->query("SELECT * FROM db_products 
WHERE owner_id='" . $user_id . "' AND active=1 '" . $filter_string . "' 
ORDER BY RAND() LIMIT 10");

$queryString = "SELECT * FROM db_products WHERE owner_id='$user_id'"
." AND active=1 "                       //Note these 
. $filter_string                        //are separated 
. "ORDER BY RAND() LIMIT 10 ";          //into individual lines

$sql_more_items = $db->query($queryString);

其中user\u id='12345'和active=1'以及product\u id=0001和产品标识=0002'按兰特订购…

---

我做错了什么？

$filter\u string

添加了

”

，因为您把它放在了那里：P

请尝试在

$filter\u string

周围加上双引号：

$sql_more_items = $db->query("SELECT * FROM db_products WHERE owner_id='" . $user_id . "' AND active=1 " . $filter_string . "ORDER BY RAND() LIMIT 10");

---

$filter\u string

添加了

”

，因为您将其放在了那里：P

请尝试在

$filter\u string

周围加上双引号：

$sql_more_items = $db->query("SELECT * FROM db_products WHERE owner_id='" . $user_id . "' AND active=1 " . $filter_string . "ORDER BY RAND() LIMIT 10");

---

那可能是因为这个角色

`"' AND active=1 '"`
                 ^.... This ' here

---

那可能是因为这个角色

`"' AND active=1 '"`
                 ^.... This ' here

检查执行字符串连接（组合字符串）的方式。当您使用“”而不是仅使用“”时，似乎出现了复制/粘贴错误

我会使用空白（和一个好的代码编辑器），通过将代码重新格式化为如下所示，为您带来好处：

while ($all_products = $db->fetch_array($all_prods))
        {
            $filter_string .= 'AND product_id !=';
            $filter_string .= $all_products['item_id'];
            $filter_string .= ' ';
}

$sql_more_items = $db->query("SELECT * FROM db_products 
WHERE owner_id='" . $user_id . "' AND active=1 '" . $filter_string . "' 
ORDER BY RAND() LIMIT 10");

$queryString = "SELECT * FROM db_products WHERE owner_id='$user_id'"
." AND active=1 "                       //Note these 
. $filter_string                        //are separated 
. "ORDER BY RAND() LIMIT 10 ";          //into individual lines

$sql_more_items = $db->query($queryString);

这种风格有助于跟踪字符串是否使用“或”，也有助于比将其放入一个巨大的难读字符串更容易调试

检查您执行字符串连接（组合字符串）的方式。当您使用“”而不仅仅是“”时，似乎出现了复制/粘贴错误

我会使用空白（和一个好的代码编辑器），通过将代码重新格式化为如下所示，为您带来好处：

while ($all_products = $db->fetch_array($all_prods))
        {
            $filter_string .= 'AND product_id !=';
            $filter_string .= $all_products['item_id'];
            $filter_string .= ' ';
}

$sql_more_items = $db->query("SELECT * FROM db_products 
WHERE owner_id='" . $user_id . "' AND active=1 '" . $filter_string . "' 
ORDER BY RAND() LIMIT 10");

$queryString = "SELECT * FROM db_products WHERE owner_id='$user_id'"
." AND active=1 "                       //Note these 
. $filter_string                        //are separated 
. "ORDER BY RAND() LIMIT 10 ";          //into individual lines

$sql_more_items = $db->query($queryString);

---

这种风格有助于您跟踪字符串是否使用“或”，也有助于您比将其放入一个巨大的难读字符串中更轻松地调试东西。

Doh！谢谢：）很快就要睡觉了：P@user1227914或者更多的咖啡！：）你愿意接受我的回答吗？他不能，除非15分钟过去，耐心点+我很感谢你这么快就抓住了它。是的，马上就好了……它告诉我要等10分钟。别担心：）@user1227914 B-）谢谢你，朋友！啊！谢谢：）很快就要睡觉了：P@user1227914或者更多的咖啡！：）你愿意接受我的回答吗？他不能，除非15分钟过去，耐心点+我很感谢你这么快就抓住了它。是的，马上就好了……它告诉我要等10分钟。别担心：）@user1227914 B-）谢谢你，朋友！