php - 如何在mysql查询中写入字符串变量？

Question

我想实现这个查询:

if(x=1){
$update = "close = '$date'";
}
else {
$update = "open = '$date'";
}
$query = "Update table1 set $update where id=100";
mysql_query($query);

但是我得到一个错误，Mysql无法执行查询？

Answer 1

   <?php
    if($x==1){
    $update = "close = '".$date."'";
    }
    else {
    $update = "open = '".$date."'";
    }
    $query = "update table1 set $update where id=100";
    mysql_query($query);
    ?>