完全编辑: 我的查询有来自 2 个表的 2 列:文件名和排序顺序。
完整的表格在这里完成 http://sqlfiddle.com/#!9/8c0507
示例:
SELECT * FROM table1 t1
LEFT JOIN table2 t2
ON t1.idmd5 = t2.imgid
ORDER BY t2.filename
WHERE t1.anotherid = "123456";
输出:
filename-01.jpg - 12
filename-02.jpg - 73
filename-03.jpg - 1
filename-12.jpg - 63
filename-24.jpg - 99
现在,“sortorder”列应该根据 ORDER BY - 输出重新设置,它应该从 1 开始。
预期结果:
filename-01.jpg - 1
filename-02.jpg - 2
filename-03.jpg - 3
filename-12.jpg - 4
filename-24.jpg - 5
如何实现这一目标?
最佳答案
这是查询:
- 在
ASCENDING ORDER
中排序后为每个文件名分配行号. - 稍后制作
INNER JOIN
表别名t
之间和你的 表YT
匹配文件名并设置t.rn (row number/new sort order)
到YT.sortOrder
专栏。
UPDATE
your_table YT
INNER JOIN
(
SELECT
fileName,
@rowNumber := @rowNumber + 1 AS rn
FROM your_table , (SELECT @rowNumber := 0) var
ORDER BY fileName ASC
) AS t
ON YT.fileName = t.fileName
SET YT.sortOrder = t.rn;
<小时/>
访问 SQL FIDDLE 时遇到问题
测试架构(带数据):
DROP TABLE IF EXISTS `your_table`;
CREATE TABLE `your_table` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`filename` varchar(50) NOT NULL,
`sortOrder` int(11) NOT NULL,
PRIMARY KEY (`id`)
);
INSERT INTO `your_table` VALUES ('1', 'f1', '12');
INSERT INTO `your_table` VALUES ('2', 'f2', '73');
INSERT INTO `your_table` VALUES ('3', 'f3', '1');
INSERT INTO `your_table` VALUES ('4', 'f4', '63');
INSERT INTO `your_table` VALUES ('5', 'f5', '99');
SELECT
*
FROM your_table;
id filename sortOrder
1 f1 12
2 f2 73
3 f3 1
4 f4 63
5 f5 99
**Now Run the above query**
SELECT
*
FROM your_table;
最终输出:
id filename sortOrder
1 f1 1
2 f2 2
3 f3 3
4 f4 4
5 f5 5
编辑:(基于要求的更改)
UPDATE
tableone TOne
INNER JOIN
(
SELECT
t1.file_id,
t2.IMG_FILENAME,
@rowNumber := @rowNumber + 1 AS rn
FROM
tableone t1
LEFT JOIN tabletwo t2 ON t1.FILE_ID = t2.IMG_ID
CROSS JOIN (SELECT @rowNumber := 0) AS var
ORDER BY t2.IMG_FILENAME ASC
) AS t
ON TOne.file_id = t.file_id
SET TOne.Order = t.rn;
测试数据和架构:
DROP TABLE IF EXISTS `tableone`;
CREATE TABLE `tableone` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`order` int(11) NOT NULL,
`file_id` int(11) NOT NULL,
PRIMARY KEY (`id`)
);
INSERT INTO `tableone` VALUES ('1', '12', '1');
INSERT INTO `tableone` VALUES ('2', '73', '2');
INSERT INTO `tableone` VALUES ('3', '1', '3');
INSERT INTO `tableone` VALUES ('4', '63', '4');
INSERT INTO `tableone` VALUES ('5', '99', '5');
DROP TABLE IF EXISTS `tabletwo`;
CREATE TABLE `tabletwo` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`img_id` int(11) NOT NULL,
`img_filename` varchar(50) NOT NULL,
PRIMARY KEY (`id`)
);
INSERT INTO `tabletwo` VALUES ('1', '1', 'filename-01.jpg ');
INSERT INTO `tabletwo` VALUES ('2', '2', 'filename-02.jpg ');
INSERT INTO `tabletwo` VALUES ('3', '3', 'filename-03.jpg ');
INSERT INTO `tabletwo` VALUES ('4', '4', 'filename-04.jpg ');
INSERT INTO `tabletwo` VALUES ('5', '5', 'filename-05.jpg ');
运行上述 ( UPDATE
) 查询操作并查看结果
更新前:SQL FIDDLE DEMO
更新后:SQL FIDDLE DEMO
关于MySQL:根据 ORDER BY 更新 "sort"列,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/38357583/