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[英]setting MySQL auto_increment to be dependent on two other primary keys
[英]1 auto_increment with 2 primary keys
我的意图是创建一个带有2个主键的表,其中一个自动递增,另一个在插入时指定,当我为该表创建新字段时,如果未递增的主键发生更改,则必须开始重新计数。 这就是我所拥有的:
我已经能够将表引擎更改为MyISAM。 但是缺少一些东西, auto_increment
不能像以前那样从100开始。
CREATE TABLE CONFIGURABLES(
CODIEI2 INTEGER AUTO_INCREMENT,
CODIEI1 INTEGER,
SKU VARCHAR(30),
COLOR INTEGER,
COLOR2 INTEGER,
TALLA INTEGER,
CONSTRAINT PK_CODIEI PRIMARY KEY(CODIEI1,CODIEI2),
CONSTRAINT FK_CODIEI1 FOREIGN KEY(CODIEI1) REFERENCES PRODUCTOS(ENTITY_ID) ON DELETE CASCADE,
CONSTRAINT FK_CCOLOR FOREIGN KEY(COLOR) REFERENCES COLORES(CODICOL) ON DELETE CASCADE,
CONSTRAINT FK_CCOLOR2 FOREIGN KEY(COLOR2) REFERENCES COLORES(CODICOL) ON DELETE CASCADE,
CONSTRAINT FK_CTALLA FOREIGN KEY(TALLA) REFERENCES TALLAS(CODITLL) ON DELETE CASCADE) ENGINE=MyISAM;
ALTER TABLE CONFIGURABLES AUTO_INCREMENT = 100;
发生这种情况是因为当auto_increment
值与auto_increment
值不同时,必须将引擎设置为InnoDB吗?
有没有一种方法可以让我想要?
解:
该表可以返回到更好的InnoDB上,并且不需要CONFIGURABLES
表上的auto_increment
,因为在执行插入时将对其进行控制。
CREATE TABLE CONFIGURABLES(
CODIEI2 INTEGER,
CODIEI1 INTEGER,
SKU VARCHAR(30),
COLOR INTEGER,
COLOR2 INTEGER,
TALLA INTEGER,
CONSTRAINT PK_CODIEI PRIMARY KEY(CODIEI1,CODIEI2),
CONSTRAINT FK_CODIEI1 FOREIGN KEY(CODIEI1) REFERENCES PRODUCTOS(ENTITY_ID) ON DELETE CASCADE,
CONSTRAINT FK_CCOLOR FOREIGN KEY(COLOR) REFERENCES COLORES(CODICOL) ON DELETE CASCADE,
CONSTRAINT FK_CCOLOR2 FOREIGN KEY(COLOR2) REFERENCES COLORES(CODICOL) ON DELETE CASCADE,
CONSTRAINT FK_CTALLA FOREIGN KEY(TALLA) REFERENCES TALLAS(CODITLL) ON DELETE CASCADE);
并在执行插入操作时执行以下操作:
BEGIN;
SELECT @id := IFNULL(MAX(CODIEI2)+1,100) FROM CONFIGURABLES WHERE CODIEI1 = 10001 FOR UPDATE;
INSERT INTO CONFIGURABLES
(CODIEI1,CODIEI2,SKU,COLOR,COLOR2,TALLA)
VALUES
(10001,@id,'',4,2,2);
COMMIT;
BEGIN;
SELECT @id := MAX(id)+1 FROM foo WHERE other = 123 FOR UPDATE;
INSERT INTO foo
(other, id, ...)
VALUES
(123, @id, ...);
COMMIT;
您如何插入数据? 如果同时将CODIEI2设置为列和值,则这将覆盖auto_increment。
在SQLFiddle中测试:
构建模式:
CREATE TABLE CONFIGURABLES(
CODIEI2 INTEGER AUTO_INCREMENT,
CODIEI1 INTEGER,
CONSTRAINT PK_CODIEI PRIMARY KEY(CODIEI2));
ALTER TABLE CONFIGURABLES AUTO_INCREMENT = 100;
INSERT INTO CONFIGURABLES ( CODIEI1 )
VALUES ( 1 );
现在覆盖auto_increment:
INSERT INTO CONFIGURABLES ( CODIEI2, CODIEI1 )
VALUES ( 1, 2 );
运行SQL:
SELECT *
FROM CONFIGURABLES;
输出:
CODIEI2 CODIEI1
1 2
100 1
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