在这种情况下如何在IN语句中使用for循环？ [英] How can I use for loop in a IN statement in this situation?

问题描述

我正在使用for循环select in。我遇到的问题是我在IN语句中有多个值。我知道 IN（term_1，term_2）我们需要一段时间来分隔每一个。当我使用循环，我不知道如何追加时间。首先，它是在语句括号内，而不是在最后。

 <？php 
 for（$ i = 0; $ i <= 8; $ i ++）{
 $ stm = $ db-> prepare（SELECT id FROM sign WHERE term IN（：term_ $ i）GROUP BY os.user_id order by COUNT （os.user_id）DESC）; 
 
 $ stm-> bindParam（：term_ $ i，$ search_text [$ i]）; 
 
 $ stm-> execute（）; 
} 
 
？> 
  

解决方案

准备语句占位符只能表示SINGLE值。例如

  $ foo ='1,2,3'; 
 $ db-> prepare（SELECT ... WHERE foo in（：foo））; 
 bind（'：foo'，$ foo）; 
  

会创建一个查询，解释为

  SELECT ... where foo IN（'1,2,3'）; 
  

请注意引号 - 您的三个单独的数字现在是一个单值字符串，如果是这样写的：

  SELECT ... WHERE foo ='1,2,3'
  code> 

您必须构建一个动态语句，并创建任意数量的占位符。

  foreach（$ values as $ val）{
 $ placeholders [] ='？'; 
 
 $ sql =SELECT ... WHERE foo IN（。implode（'，'，$ placeholders）。）; 
 ...准备/绑定其他值
 $ stmt->执行（$ values）; 
  




I am using for loop for select in. The issue I am encounter is I have multiple value in the IN statement. I know IN(term_1, term_2) we need a period to separate each one. When I use for loop, I don't know how to append the period. First, it was inside the statement parenthesis instead of at the end.

<?php
for ($i = 0; $i <= 8; $i++) {
    $stm =$db->prepare("SELECT id FROM sign WHERE term IN (:term_$i) GROUP BY os.user_id order by COUNT(os.user_id) DESC ");

        $stm->bindParam(":term_$i", $search_text[$i]);

        $stm->execute();
    }

?>

解决方案

Prepared statement placeholders can only represent SINGLE values.

e.g.

$foo = '1,2,3';
$db->prepare("SELECT ... WHERE foo in (:foo)");
bind(':foo', $foo);

would create a query that's interpreted as

SELECT ... WHERE foo IN ('1,2,3');

Note the quotes - your three separate numbers are now a single-valued string, and the query runs as if it had been written:

SELECT ... WHERE foo='1,2,3'

You'd have to build a dynamic statement and create as many placeholders as you have values.

foreach ($values as $val) {
     $placeholders[] = '?';
}
$sql = "SELECT ... WHERE foo IN (" . implode(',', $placeholders) . ")";
...prepare/bind other values
$stmt->execute($values);

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