[英]How to insert a php variable in an sql query? Mistake in my query?
我写了这个简单的代码来从sql表中删除一个博客。 但它给出了一个错误
Could not delete data: Unknown column '$qid' in 'where clause'
不明白为什么。 $qid
是变量,而qid
是列名,它给我这个错误。
<?php
$dbhost = 'localhost';
$dbuser = 'root';
$dbpass = '';
$conn = mysql_connect($dbhost, $dbuser, $dbpass);
mysql_select_db('trial1');
if(! $conn )
{
die('Could not connect: ' . mysql_error());
}
function check_login(){
return 12;
}
$return_array = array();
if( check_login()!=NULL){
$qid =1;
$sql='DELETE FROM blog_post WHERE qid = $qid';
$retval = mysql_query($sql, $conn);
if (!$retval){
die('Could not delete data: ' . mysql_error());
$return_array["success"] = 0; //If deletion unsuccessful
echo json_encode($return_array);
}
else{
$return_array["success"]=1; //If deletion successful
echo json_encode($return_array);
}
}
?>
您应该使用单引号将输入包装在sql中:
$sql="DELETE FROM `blog_post` WHERE `qid` = '$qid'";
首先,您需要确保表中有列名qid 。
然后尝试:
$sql='DELETE FROM blog_post WHERE qid ='.$qid;
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