[英]Multiple mysql updates in single query
我有一个名为member_photos
的表,该表存储member_id
, photo_id
, photo_dir
和photo_name
,当有人编辑他的照片时,它发布了有关照片的数组信息,发布的页面具有包含照片信息的数组,但是我的问题是我使用了foreach循环并更新了每个一张一张地合影
UPDATE member_photos
SET photo_name = '$newphotoname'
WHERE photo_id = '$photoid'
可以,但是当这个人有20张照片时,数组有20个项目,因此循环将执行20个查询。 有什么方法可以通过一次查询更新所有照片?
UPDATE categories
SET display_order = CASE id
WHEN 1 THEN 3
WHEN 2 THEN 4
WHEN 3 THEN 5
END,
title = CASE id
WHEN 1 THEN 'New Title 1'
WHEN 2 THEN 'New Title 2'
WHEN 3 THEN 'New Title 3'
END
WHERE id IN (1,2,3)
在PHP中
// An array containing the category ids as keys and the new positions as values
$display_order = array(
1 => 4,
2 => 1,
3 => 2,
4 => 3,
5 => 9,
6 => 5,
7 => 8,
8 => 9
);
$ids = implode(',', array_keys($display_order));
$sql = "UPDATE categories SET display_order = CASE id ";
foreach ($display_order as $id => $ordinal) {
$sql .= sprintf("WHEN %d THEN %d ", $id, $ordinal);
}
$sql .= "END WHERE id IN ($ids)";
echo $sql;
此信息的资源: http : //www.karlrixon.co.uk/writing/update-update-multiple-rows-with-different-values-and-a-single-sql-query/
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