在当前表上使用子查询的Mariadb检查约束
在当前表上使用子查询的Mariadb检查约束
提问于 2018-06-09 20:05:39
是否可以这样对子查询maria db表进行检查约束：
CREATE TABLE `tbl` (
`id` int NOT NULL,
`start` datetime NOT NULL,
`end` datetime NOT NULL,
CONSTRAINT C1 CHECK (id not in (select id from tbl as tt where tt.start between start and end or tt.end between start and end)),
CONSTRAINT C2 CHECK (end>start)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;我收到错误:错误1146 (42S02)：表'test.tbl‘不存在
回答 1
Stack Overflow用户
发布于 2018-06-10 01:11:11
您正在尝试访问一个不存在的对象(表'tbl')，您正在尝试创建它：
MariaDB [_]> DROP TABLE IF EXISTS `tbl`;
Query OK, 0 rows affected (0.01 sec)
MariaDB [_]> CREATE TABLE IF NOT EXISTS `tbl` (
-> `id` INT NOT NULL,
-> `start` DATETIME NOT NULL,
-> `end` DATETIME NOT NULL,
-> CONSTRAINT `C1` CHECK (`id` NOT IN
-> (SELECT `id`
-> FROM `tbl` AS `tt`
-> WHERE `tt`.`start` BETWEEN `start` AND `end` OR
-> `tt`.`end` BETWEEN `start` AND `end`)
-> ),
-> CONSTRAINT `C2` CHECK (`end` > `start`)
-> );
ERROR 1146 (42S02): Table '_.tbl' doesn't exist在访问确实存在的对象的情况下：
MariaDB [_]> DROP TABLE IF EXISTS `tbl_TEMP`, `tbl`;
Query OK, 0 rows affected, 2 warnings (0.00 sec)
MariaDB [_]> CREATE TABLE IF NOT EXISTS `tbl_TEMP` (
-> `id` INT NOT NULL,
-> `start` DATETIME NOT NULL,
-> `end` DATETIME NOT NULL
-> );
Query OK, 0 rows affected (0.00 sec)
MariaDB [_]> CREATE TABLE IF NOT EXISTS `tbl` (
-> `id` INT NOT NULL,
-> `start` DATETIME NOT NULL,
-> `end` DATETIME NOT NULL,
-> CONSTRAINT `C1` CHECK (
-> `id` NOT IN (SELECT `id`
-> FROM `tbl_TEMP` AS `tt`
-> WHERE `tt`.`start` BETWEEN `start` AND `end` OR
-> `tt`.`end` BETWEEN `start` AND `end`)
-> ),
-> CONSTRAINT `C2` CHECK (`end` > `start`)
-> );
ERROR 1901 (HY000): Function or expression 'select ...'
cannot be used in the CHECK clause of `C1`一个可能有用的选项：
MariaDB [_]> DROP TABLE IF EXISTS `tbl`;
Query OK, 0 rows affected, 1 warning (0.00 sec)
MariaDB [_]> CREATE TABLE IF NOT EXISTS `tbl` (
-> `id` INT NOT NULL,
-> `start` DATETIME NOT NULL,
-> `end` DATETIME NOT NULL,
-> CONSTRAINT `C2` CHECK (`end` > `start`)
-> );
Query OK, 0 rows affected (0.00 sec)
MariaDB [_]> DELIMITER //
MariaDB [_]> CREATE TRIGGER `trg_bi_idduplicate` BEFORE INSERT ON `tbl`
-> FOR EACH ROW
-> BEGIN
-> IF EXISTS (SELECT NULL
-> FROM `tbl`
-> WHERE `id` = NEW.`id`) THEN
-> SIGNAL SQLSTATE '45000' SET
-> MYSQL_ERRNO = 31001,
-> MESSAGE_TEXT = '`id` DUPLICATE';
-> END IF;
-> END//
Query OK, 0 rows affected (0.00 sec)
MariaDB [_]> DELIMITER ;
MariaDB [_]> INSERT INTO `tbl`
-> SELECT 1, '2000-01-01 00:00:01', '2000-01-01 00:00:01';
ERROR 4025 (23000): CONSTRAINT `C2` failed for `_`.`tbl`
MariaDB [_]> INSERT INTO `tbl`
-> SELECT 1, '2000-01-01 00:00:01', '2000-01-01 00:00:02';
Query OK, 1 row affected (0.00 sec)
Records: 1 Duplicates: 0 Warnings: 0
MariaDB [_]> SELECT
-> `id`,
-> `start`,
-> `end`
-> FROM
-> `tbl`;
+----+---------------------+---------------------+
| id | start | end |
+----+---------------------+---------------------+
| 1 | 2000-01-01 00:00:01 | 2000-01-01 00:00:02 |
+----+---------------------+---------------------+
1 row in set (0.00 sec)
MariaDB [_]> INSERT INTO `tbl`
-> SELECT 1, '2000-01-01 00:00:01', '2000-01-01 00:00:02';
ERROR 31001 (45000): `id` DUPLICATE
MariaDB [_]> SELECT
-> `id`,
-> `start`,
-> `end`
-> FROM
-> `tbl`;
+----+---------------------+---------------------+
| id | start | end |
+----+---------------------+---------------------+
| 1 | 2000-01-01 00:00:01 | 2000-01-01 00:00:02 |
+----+---------------------+---------------------+
1 row in set (0.00 sec)页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/50774098
复制相关文章
相似问题