我正在创建一个程序,我从一个表中选择的数据被随机分组 . 每个组中的RegistrationID号被保存到另一个表中(作为外键),并为每个组成员分配一个groupID,该ID随创建的每个新组自动递增 .
$GroupSize = $_POST['groupsize'];
//Connect to the Server+Select DB
$con = mysqli_connect($host, $user, $password, $dbName) or die("Nope");
if (isset($_POST['create'])) {
//assign group id to groups created
//insert groupinformation to table from userInformation
$query = "SELECT RegistrationId FROM (Select * from userInformation order by RAND() LIMIT ".$GroupSize.") INTO groupInformation";
$result = mysqli_query($con, $query) or die ("query failed" . mysqli_error($con));
//display group and information
echo "<table border='1' >";
echo "<tr><th>RegId</th><th>Name</th><th>Address</th><th>Email</th></tr>";
while (($row = mysqli_fetch_row($result)) == true) {
echo "<tr><td>$row[0]</td><td>$row[1]</td><td>$row[2]</td><td>$row[3]</td></tr>";
}
echo "</table>";
//if group is less than 2 create error message
}
mysqli_close($con);
我的问题是我无法将GroupId分配给提取的结果,因为无法复制自动递增的数字 . 这是我的错误:
query failed Every derived table must have its own alias
这是我的表架构
1 回答
让
GroupId
自动增量,然后在groupInformation
中再创建一个RandomGroupId
列,然后粘贴查询: