我有一个表,我添加了一个名为 phone
的列 - 该表还有一个 id 设置为 auto_increments 的主键。如何在电话列中插入一个随机值,该值不会被复制。以下 UPDATE 语句确实插入了随机值,但并非所有值都是唯一的。另外,我不卖我也正确地转换了 phone
字段,但是在尝试将它设置为带有 ALTER TABLE 命令的 int(11) 时遇到了问题(主要是,它运行正确,但是当添加带有新电话号码的行时,插入的值被转换为不同的号码)。
UPDATE Ballot SET phone = FLOOR(50000000 * RAND()) + 1;
表格规范
+------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +------------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | phone | varchar(11) | NO | | NULL | | | age | tinyint(3) | NO | | NULL | | | test | tinyint(4) | NO | | 0 | | | note | varchar(100) | YES | | NULL | | +------------+--------------+------+-----+---------+----------------+
最佳答案
-- tbl_name: Table
-- column_name: Column
-- chars_str: String containing acceptable characters
-- n: Length of the random string
-- dummy_tbl: Not a parameter, leave as is!
UPDATE tbl_name SET column_name = (
SELECT GROUP_CONCAT(SUBSTRING(chars_str , 1+ FLOOR(RAND()*LENGTH(chars_str)) ,1) SEPARATOR '')
FROM (SELECT 1 /* UNION SELECT 2 ... UNION SELECT n */) AS dummy_tbl
);
-- Example
UPDATE tickets SET code = (
SELECT GROUP_CONCAT(SUBSTRING('123abcABC-_$@' , 1+ FLOOR(RAND()*LENGTH('123abcABC-_$@')) ,1) SEPARATOR '')
FROM (SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5) AS dummy_tbl
);
关于MySQL Alter table,添加具有唯一随机值的列,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/4661144/