如何使用 MySQL InnoDB 实现 auto_increment 复合主键？
How to implement an auto_increment composite primary key with MySQL InnoDB?
我有一个 table，它有一个复合主键，由一个 non-auto_increment 列和一个 auto_increment 列组成。 auto_increment 列需要为每个 non-auto_increment 列值单独递增（稍后会详细介绍）。存储引擎是InnoDB。出于性能方面的考虑，我不想锁定 table。插入一个值后，检索最后一个 auto_increment 值的方法必须可用。
下面的脚本起初有效，但最后的 INSERT 结果是 id，checkingaccounts_id 是 3, 2，但需要 1, 2。这就是我所说的 The auto_increment column needs to increment individually for each of the non-auto_increment column values
触发器和存储过程都是acceptable，PHP/PDO 应用程序解决方案也是如此，它以某种方式模仿MySQL auto_increment 行为。
mysql> EXPLAIN checkingaccounts;
+-------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| data | varchar(45) | YES | | NULL | |
+-------+-------------+------+-----+---------+----------------+
2 rows in set (0.00 sec)
mysql> EXPLAIN checks;
+---------------------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------------------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| checkingaccounts_id | int(11) | NO | PRI | NULL | |
| data | varchar(45) | YES | | NULL | |
+---------------------+-------------+------+-----+---------+----------------+
3 rows in set (0.00 sec)
mysql> INSERT INTO checkingaccounts(id, data) VALUES(0,'bla');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO checkingaccounts(id, data) VALUES(0,'bla');
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM checkingaccounts;
+----+------+
| id | data |
+----+------+
| 1 | bla |
| 2 | bla |
+----+------+
2 rows in set (0.00 sec)
mysql> INSERT INTO checks(id,checkingaccounts_id,data) VALUES(0,1,'bla');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO checks(id,checkingaccounts_id,data) VALUES(0,1,'bla');
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM checks;
+----+---------------------+------+
| id | checkingaccounts_id | data |
+----+---------------------+------+
| 1 | 1 | bla |
| 2 | 1 | bla |
+----+---------------------+------+
2 rows in set (0.00 sec)
mysql> INSERT INTO checks(id,checkingaccounts_id,data) VALUES(0,2,'bla');
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM checks;
+----+---------------------+------+
| id | checkingaccounts_id | data |
+----+---------------------+------+
| 1 | 1 | bla |
| 2 | 1 | bla |
| 3 | 2 | bla |
+----+---------------------+------+
3 rows in set (0.00 sec)
mysql>
删除 auto_increment 功能，改用存储过程：
CREATE PROCEDURE insertChecks
(IN AccID int(9), IN data varchar(50))
BEGIN
DECLARE cid INT DEFAULT 1;
SELECT (COUNT(*) + 1) INTO cid
FROM checks
WHERE checkingaccounts_id = AccID;
INSERT INTO checks(id, checkingaccounts_id, data)
VALUES(cid, AccID, data);
END
和
call insertChecks(1,'bla');
call insertChecks(1,'bla');
call insertChecks(2,'bla');
解决方案 2：
CREATE PROCEDURE insertChecks
(IN AccID int(9), IN data varchar(50))
BEGIN
INSERT INTO checks(id, checkingaccounts_id, data)
SELECT (COUNT(*) + 1), AccID, data
FROM checks
WHERE checkingaccounts_id = AccID;
END
创建一个 MyISAM table 以仅创建 auto_increment id，并使用触发器将此 id 用于目标 table。如果有多个 InnoDB tables 需要一个复合 auto_incrementing 主键，添加一个额外的主键到 MyISAM table.
缺点：
- MyISAM 上不允许外键约束 table，但是，希望触发器可以消除风险。
- 需要额外的 table。
优势
- 如果删除主键阀，将不会重复使用。
- 客户端只使用普通的 SQL 查询而不是存储过程。
- 可能比存储过程维护更少，因为向 table 添加列不需要修改触发器。
-- MySQL Script generated by MySQL Workbench
-- 07/08/16 05:12:11
-- Model: New Model Version: 1.0
SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0;
SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0;
SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='TRADITIONAL,ALLOW_INVALID_DATES';
-- -----------------------------------------------------
-- Schema mydb
-- -----------------------------------------------------
CREATE SCHEMA IF NOT EXISTS `mydb` DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci ;
USE `mydb` ;
-- -----------------------------------------------------
-- Table `mydb`.`a`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`a` (
`id` INT NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`))
ENGINE = InnoDB;
-- -----------------------------------------------------
-- Table `mydb`.`t1`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`t1` (
`a_id` INT NOT NULL,
`id` INT NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`, `a_id`),
CONSTRAINT `fk_t1_a1`
FOREIGN KEY (`a_id`)
REFERENCES `mydb`.`a` (`id`)
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
-- -----------------------------------------------------
-- Table `mydb`.`t2`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`t2` (
`a_id` INT NOT NULL,
`id` INT NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`, `a_id`),
CONSTRAINT `fk_t2_a1`
FOREIGN KEY (`a_id`)
REFERENCES `mydb`.`a` (`id`)
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
-- -----------------------------------------------------
-- Table `mydb`.`t3`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`t3` (
`a_id` INT NOT NULL,
`id` INT NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`, `a_id`),
CONSTRAINT `fk_t3_a1`
FOREIGN KEY (`a_id`)
REFERENCES `mydb`.`a` (`id`)
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
-- -----------------------------------------------------
-- Table `mydb`.`inc`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`inc` (
`a_id` INT NOT NULL,
`id` INT NOT NULL AUTO_INCREMENT,
`type` CHAR(4) NOT NULL,
PRIMARY KEY (`a_id`, `type`, `id`))
ENGINE = MyISAM;
SET SQL_MODE=@OLD_SQL_MODE;
SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS;
SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS;
USE `mydb`;
DELIMITER $$
USE `mydb`$$
CREATE TRIGGER `t1_BINS` BEFORE INSERT ON `t1` FOR EACH ROW
BEGIN
INSERT INTO inc(a_id,type) VALUES(NEW.a_id,'t1');
SET NEW.id=LAST_INSERT_ID();
END$$
USE `mydb`$$
CREATE TRIGGER `t2_BINS` BEFORE INSERT ON `t2` FOR EACH ROW
BEGIN
INSERT INTO inc(a_id,type) VALUES(NEW.a_id,'t2');
SET NEW.id=LAST_INSERT_ID();
END$$
USE `mydb`$$
CREATE TRIGGER `t3_BINS` BEFORE INSERT ON `t3` FOR EACH ROW
BEGIN
INSERT INTO inc(a_id,type) VALUES(NEW.a_id,'t3');
SET NEW.id=LAST_INSERT_ID();
END$$
DELIMITER ;
测试
mysql> insert into a(id) VALUES(null);
Query OK, 1 row affected (0.00 sec)
mysql> insert into t1(a_id) VALUES(1);
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM t1;
+------+----+
| a_id | id |
+------+----+
| 1 | 1 |
+------+----+
1 row in set (0.00 sec)
mysql> insert into t1(a_id) VALUES(1);
Query OK, 1 row affected (0.00 sec)
mysql> insert into t1(a_id) VALUES(1);
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM t1;
+------+----+
| a_id | id |
+------+----+
| 1 | 1 |
| 1 | 2 |
| 1 | 3 |
+------+----+
3 rows in set (0.00 sec)
mysql> insert into t2(a_id) VALUES(1);
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM t2;
+------+----+
| a_id | id |
+------+----+
| 1 | 1 |
+------+----+
1 row in set (0.00 sec)
mysql> insert into a(id) VALUES(null);
Query OK, 1 row affected (0.00 sec)
mysql> insert into a(id) VALUES(null);
Query OK, 1 row affected (0.00 sec)
mysql> insert into t1(a_id) VALUES(2);
Query OK, 1 row affected (0.00 sec)
mysql> insert into t1(a_id) VALUES(3);
Query OK, 1 row affected (0.00 sec)
mysql> insert into t1(a_id) VALUES(1);
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM t1;
+------+----+
| a_id | id |
+------+----+
| 1 | 1 |
| 1 | 2 |
| 1 | 3 |
| 1 | 4 |
| 2 | 1 |
| 3 | 1 |
+------+----+
6 rows in set (0.00 sec)
mysql>
我有一个 table，它有一个复合主键，由一个 non-auto_increment 列和一个 auto_increment 列组成。 auto_increment 列需要为每个 non-auto_increment 列值单独递增（稍后会详细介绍）。存储引擎是InnoDB。出于性能方面的考虑，我不想锁定 table。插入一个值后，检索最后一个 auto_increment 值的方法必须可用。
下面的脚本起初有效，但最后的 INSERT 结果是 id，checkingaccounts_id 是 3, 2，但需要 1, 2。这就是我所说的 The auto_increment column needs to increment individually for each of the non-auto_increment column values
触发器和存储过程都是acceptable，PHP/PDO 应用程序解决方案也是如此，它以某种方式模仿MySQL auto_increment 行为。
mysql> EXPLAIN checkingaccounts;
+-------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| data | varchar(45) | YES | | NULL | |
+-------+-------------+------+-----+---------+----------------+
2 rows in set (0.00 sec)
mysql> EXPLAIN checks;
+---------------------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------------------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| checkingaccounts_id | int(11) | NO | PRI | NULL | |
| data | varchar(45) | YES | | NULL | |
+---------------------+-------------+------+-----+---------+----------------+
3 rows in set (0.00 sec)
mysql> INSERT INTO checkingaccounts(id, data) VALUES(0,'bla');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO checkingaccounts(id, data) VALUES(0,'bla');
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM checkingaccounts;
+----+------+
| id | data |
+----+------+
| 1 | bla |
| 2 | bla |
+----+------+
2 rows in set (0.00 sec)
mysql> INSERT INTO checks(id,checkingaccounts_id,data) VALUES(0,1,'bla');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO checks(id,checkingaccounts_id,data) VALUES(0,1,'bla');
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM checks;
+----+---------------------+------+
| id | checkingaccounts_id | data |
+----+---------------------+------+
| 1 | 1 | bla |
| 2 | 1 | bla |
+----+---------------------+------+
2 rows in set (0.00 sec)
mysql> INSERT INTO checks(id,checkingaccounts_id,data) VALUES(0,2,'bla');
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM checks;
+----+---------------------+------+
| id | checkingaccounts_id | data |
+----+---------------------+------+
| 1 | 1 | bla |
| 2 | 1 | bla |
| 3 | 2 | bla |
+----+---------------------+------+
3 rows in set (0.00 sec)
mysql>
删除 auto_increment 功能，改用存储过程：
CREATE PROCEDURE insertChecks
(IN AccID int(9), IN data varchar(50))
BEGIN
DECLARE cid INT DEFAULT 1;
SELECT (COUNT(*) + 1) INTO cid
FROM checks
WHERE checkingaccounts_id = AccID;
INSERT INTO checks(id, checkingaccounts_id, data)
VALUES(cid, AccID, data);
END
和
call insertChecks(1,'bla');
call insertChecks(1,'bla');
call insertChecks(2,'bla');
解决方案 2：
CREATE PROCEDURE insertChecks
(IN AccID int(9), IN data varchar(50))
BEGIN
INSERT INTO checks(id, checkingaccounts_id, data)
SELECT (COUNT(*) + 1), AccID, data
FROM checks
WHERE checkingaccounts_id = AccID;
END
创建一个 MyISAM table 以仅创建 auto_increment id，并使用触发器将此 id 用于目标 table。如果有多个 InnoDB tables 需要一个复合 auto_incrementing 主键，添加一个额外的主键到 MyISAM table.
缺点：
- MyISAM 上不允许外键约束 table，但是，希望触发器可以消除风险。
- 需要额外的 table。
优势
- 如果删除主键阀，将不会重复使用。
- 客户端只使用普通的 SQL 查询而不是存储过程。
- 可能比存储过程维护更少，因为向 table 添加列不需要修改触发器。
-- MySQL Script generated by MySQL Workbench
-- 07/08/16 05:12:11
-- Model: New Model Version: 1.0
SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0;
SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0;
SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='TRADITIONAL,ALLOW_INVALID_DATES';
-- -----------------------------------------------------
-- Schema mydb
-- -----------------------------------------------------
CREATE SCHEMA IF NOT EXISTS `mydb` DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci ;
USE `mydb` ;
-- -----------------------------------------------------
-- Table `mydb`.`a`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`a` (
`id` INT NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`))
ENGINE = InnoDB;
-- -----------------------------------------------------
-- Table `mydb`.`t1`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`t1` (
`a_id` INT NOT NULL,
`id` INT NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`, `a_id`),
CONSTRAINT `fk_t1_a1`
FOREIGN KEY (`a_id`)
REFERENCES `mydb`.`a` (`id`)
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
-- -----------------------------------------------------
-- Table `mydb`.`t2`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`t2` (
`a_id` INT NOT NULL,
`id` INT NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`, `a_id`),
CONSTRAINT `fk_t2_a1`
FOREIGN KEY (`a_id`)
REFERENCES `mydb`.`a` (`id`)
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
-- -----------------------------------------------------
-- Table `mydb`.`t3`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`t3` (
`a_id` INT NOT NULL,
`id` INT NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`, `a_id`),
CONSTRAINT `fk_t3_a1`
FOREIGN KEY (`a_id`)
REFERENCES `mydb`.`a` (`id`)
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
-- -----------------------------------------------------
-- Table `mydb`.`inc`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`inc` (
`a_id` INT NOT NULL,
`id` INT NOT NULL AUTO_INCREMENT,
`type` CHAR(4) NOT NULL,
PRIMARY KEY (`a_id`, `type`, `id`))
ENGINE = MyISAM;
SET SQL_MODE=@OLD_SQL_MODE;
SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS;
SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS;
USE `mydb`;
DELIMITER $$
USE `mydb`$$
CREATE TRIGGER `t1_BINS` BEFORE INSERT ON `t1` FOR EACH ROW
BEGIN
INSERT INTO inc(a_id,type) VALUES(NEW.a_id,'t1');
SET NEW.id=LAST_INSERT_ID();
END$$
USE `mydb`$$
CREATE TRIGGER `t2_BINS` BEFORE INSERT ON `t2` FOR EACH ROW
BEGIN
INSERT INTO inc(a_id,type) VALUES(NEW.a_id,'t2');
SET NEW.id=LAST_INSERT_ID();
END$$
USE `mydb`$$
CREATE TRIGGER `t3_BINS` BEFORE INSERT ON `t3` FOR EACH ROW
BEGIN
INSERT INTO inc(a_id,type) VALUES(NEW.a_id,'t3');
SET NEW.id=LAST_INSERT_ID();
END$$
DELIMITER ;
测试
mysql> insert into a(id) VALUES(null);
Query OK, 1 row affected (0.00 sec)
mysql> insert into t1(a_id) VALUES(1);
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM t1;
+------+----+
| a_id | id |
+------+----+
| 1 | 1 |
+------+----+
1 row in set (0.00 sec)
mysql> insert into t1(a_id) VALUES(1);
Query OK, 1 row affected (0.00 sec)
mysql> insert into t1(a_id) VALUES(1);
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM t1;
+------+----+
| a_id | id |
+------+----+
| 1 | 1 |
| 1 | 2 |
| 1 | 3 |
+------+----+
3 rows in set (0.00 sec)
mysql> insert into t2(a_id) VALUES(1);
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM t2;
+------+----+
| a_id | id |
+------+----+
| 1 | 1 |
+------+----+
1 row in set (0.00 sec)
mysql> insert into a(id) VALUES(null);
Query OK, 1 row affected (0.00 sec)
mysql> insert into a(id) VALUES(null);
Query OK, 1 row affected (0.00 sec)
mysql> insert into t1(a_id) VALUES(2);
Query OK, 1 row affected (0.00 sec)
mysql> insert into t1(a_id) VALUES(3);
Query OK, 1 row affected (0.00 sec)
mysql> insert into t1(a_id) VALUES(1);
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM t1;
+------+----+
| a_id | id |
+------+----+
| 1 | 1 |
| 1 | 2 |
| 1 | 3 |
| 1 | 4 |
| 2 | 1 |
| 3 | 1 |
+------+----+
6 rows in set (0.00 sec)
mysql>