删除最后，在PHP中生成的MySQL语句

问题描述：

I Have the following PHP script:

$i = 0;
        while ($i < 30){
            $insertquery = "INSERT INTO {$savename} VALUES (";

            foreach ($valuearray as $column){
                $insertquery .= $column[$i] . ",";
            }

            $insertquery .= ");";
            echo $insertquery;
            $queryResult = mysqli_query($con, $insertquery);
            if ($queryResult === TRUE){

            }else{
                print "<br /><br />No Row created. Check " . mysqli_error($con);
            }
            $i++;
        }

The $valuearray is a two dimensional array with everything that needs to be inserted into the table. The issue is that the above code creates a MySQL statement in the form

INSERT INTO rates_test VALUES (1000,0.1,2.3,100,2,3,);

Which gives a Syntax error as the last value has a , after it.

How could I go about changing the script so that the last value does not have a , after it, or prehaps delete it after the foreach loop?

我有以下PHP脚本： p>

  $ i =  0; 
 while（$ i＆lt; 30）{
 $ insertquery =“INSERT INTO {$ savename} VALUES（”; 
 
 foreach（$ valuearray as $ column）{
 $ insertquery。= $ column  [$ i]。“，”; 
} 
 
 $ insertquery。=“）;”; 
 echo $ insertquery; 
 $ queryResult = mysqli_query（$ con，$ insertquery）; 
 if（$  queryResult === TRUE）{
 
} else {
 print“＆lt; br /＆gt;＆lt; br /＆gt; No Row created.Check”。  mysqli_error（$ con）; 
} 
 $ i ++; 
} 
  code>  pre> 
 
  $ valuearray是一个二维数组，包含需要插入的所有内容 表格。
问题是上面的代码以 p> 
 
 
  INSERT INTO rates_test VALUES（1000,0.1,2.3,100,2,3，）的形式创建一个MySQL语句 ;  
  code>  pre> 
 
 这会产生语法错误，因为最后一个值后面有， code>。 p> 
 
 
 我怎么能改变脚本以便最后一个值在它之后没有， code>，或者在foreach循环之后删除它呢？ p> 
  div>

答

Before $insertquery .= ");"; you could use $insertquery = rtrim($insertquery, ',');

My preferred method for building IN lists though is to use implode:

"VALUES (" . implode(',', $valuearray) . ")";

It's also worth noting that you should preferably be using parameterized queries. I'm not sure whether you can bind a variable number of arguments using mysqli, but in PDO the idea would be something like:

"VALUES (" . implode(',', array_fill(0, count($valuearray), '?')) . ")";

This emits "VALUES (?,?,?)". Then you could just pass $valuearray to execute.

答

I prefer to not put it there in the first place if possible, than add something you don't want then remove it later (each to their own I guess):

foreach ($valuearray as $column)
  {
    $insertquery .= $column[$i];

    if ($i < 29)
      {
        $insertquery .= ",";
      }
  }

答

How about using implode function so you don't have to worry about the last comma

$insertquery .= implode(",", $valuearray);

PS: Seems the code is prone to SQL injection if the array comes from user input

删除最后，在PHP中生成的MySQL语句

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