We are in section 13.3 "Making a list display through steps". Before deletion, there are single row deletion of data and deletion of multiple rows of data.
Determine whether to delete a single selection or multiple selections
1. A single line is passed to the delete.php file through get parameters. Write the corresponding ID in .
2. Multiple deletions pass the corresponding ID to the delete.php page through POST.
3. If neither of these two is consistent, then we can regard the data as illegal.
if (is_array($_POST['id'])) {
$id = join(',', $_POST['id']);
} elseif (is_numeric($_GET['id'])) {
$id = (int) $_GET['id'];
} else {
echo '数据不合法';
exit;
}Combined SQL statements
We have previously explained to you in the MySQL chapter that you can use the in sub-statement when deleting.
Similarly here, we can use the in sub-statement to achieve the effect.
The join function changes the id passed by the multi-select deletion into the format of 3, 4, 5. The final effect of the SQL statement for multi-select deletion is:
delete from user where id in(3,4,5,6,8);
And single-select deletion The effect of the statement is:
delete from user where id in(3)
In this way, we achieve the single-selection and multi-selection adaptive effects.
$sql = "delete from user where id in($id)";
The final complete code demonstration is as follows:
<?php
include 'connection.php';
if (is_array($_POST['id'])) {
$id = join(',', $_POST['id']);
} elseif (is_numeric($_GET['id'])) {
$id = (int) $_GET['id'];
} else {
echo '数据不合法';
exit;
}
$sql = "delete from user where id in($id)";
$result = mysqli_query($conn, $sql);
if ($result) {
echo '删除成功';
} else {
echo '删除失败';
}
?>