我试图从数据库中提取数据,然后将返回的结果指定给变量以便进行其他搜索/删除操作,但我一直在一个错误消息说我设置的变量($ islecturer和$ group)是未定义的。如果有人能告诉我我要去哪里,我会非常感激。如何从数据库中提取数据并将其分配给变量以进行删除查询
<?php
require ('mysqli_connect.php');
$q1 = "SELECT `islecturer` FROM `participants` WHERE `uninum` = 'A17'";
$result1 = @mysqli_query($dbcon,$q1);
while ($row1 = mysqli_fetch_array ($result1, MYSQLI_ASSOC)){
$islecturer = $row1['islecturer'];
echo $islecturer;
}
if ($islecturer == 0){
$q2 = "SELECT `groupid` FROM `groups` WHERE `uninum` = 'A17'";
$result2 = @mysqli_query($dbcon,$q2);
}
while ($row2 = mysqli_fetch_array ($result2, MYSQLI_ASSOC)){
$group = $row2['groupid'];
echo $group;
}
$q3 = "DELETE FROM `schedule` WHERE `groupid` = $group LIMIT 1;";
$result3 = mysqli_multi_query ($dbcon , $q3);
$q3 .="DELETE FROM `groups` WHERE `groupid` = $group LIMIT 1;";
$result3 = mysqli_multi_query ($dbcon , $q3);
$q3 .="DELETE FROM `individualavailability` WHERE uninum = 'A17' LIMIT 1;";
$result3 = mysqli_multi_query ($dbcon , $q3);
$q3 .="DELETE FROM `availabilityindex` WHERE `uninum` = 'A17' LIMIT 1;";
$result3 = mysqli_multi_query ($dbcon , $q3);
$q3 ="DELETE FROM `participants` WHERE `uninum` = 'A17' LIMIT 1;";
$result3 = mysqli_multi_query ($dbcon , $q3);
if (mysqli_affected_rows($dbcon) > 1) { // If it ran OK.
echo 'Successfully deleted';
}
else if ($islecturer == 1){
echo 'you can\'t delete a lecturer without adding a replacement group member';
}
else{
echo 'query failed';
}
mysqli_close($dbcon);
?>
需要注意的是'A17'现在是硬编码的,但是它会从$ _POST ['uni_id']获得。 – Rodger123