php - 如何动态创建表并在列不存在时更改表

Question

enter
<?php $dob=$_SESSION['dob']; 
 $month=$_SESSION['month'];
 $exists = false;
 $columns = mysql_query("show columns from $month");
 while($c = mysql_fetch_assoc($columns)){
  if($c['Field'] == $dob){
   $exists = true;
   break;
  }
 }     
 if(!$exists){
  mysql_query("ALTER TABLE `$month`  ADD  `$dob` varchar(100) default absent");
 }
 $roll=$_SESSION['var'];
 foreach( $roll as $value=>$roll) {
  $name = mysql_real_escape_string ($roll);
  $sql="insert into $month (roll) values ('$name')";
  mysql_query($sql)or die(mysql_error());
 }
?>

问:-如何在 mysql php 中创建表和修改表？

Answer 1

要创建表，请执行以下操作:

CREATE TABLE `tableName` (
 ... Columns ...
);