DROP TABLE IF EXISTS `cloth`;
CREATE TABLE `cloth` (
`clothNo` int(4) NOT NULL AUTO_INCREMENT,
`clothID` varchar(15) NOT NULL,
`clothColor` varchar(10) DEFAULT NULL,
`clothSize` tinyint(5) DEFAULT NULL,
`clothPhoto` blob,
PRIMARY KEY (`clothNo`,`clothID`)
) ENGINE=InnoDB DEFAULT CHARSET=gb2312;如何实现让clothNo在clothID的控制下自增呢?
举例来说就是:
clothID = j1时,clothNo从1自增;
clothID = j2时,clothNo从1自增;
CREATE TABLE `cloth` (
`clothNo` int(4) NOT NULL AUTO_INCREMENT,
`clothID` varchar(15) NOT NULL,
`clothColor` varchar(10) DEFAULT NULL,
`clothSize` tinyint(5) DEFAULT NULL,
`clothPhoto` blob,
PRIMARY KEY (`clothNo`,`clothID`)
) ENGINE=InnoDB DEFAULT CHARSET=gb2312;如何实现让clothNo在clothID的控制下自增呢?
举例来说就是:
clothID = j1时,clothNo从1自增;
clothID = j2时,clothNo从1自增;
你可以试试right函数,取出clothID的右边的数字,然后赋值给clothNo
select right(clothID,1) from cloth;
`clothNo` int(4) NOT NULL AUTO_INCREMENT,
`clothID` varchar(15) NOT NULL,
`clothColor` varchar(10) DEFAULT NULL,
`clothSize` tinyint(5) DEFAULT NULL,
`clothPhoto` blob,
PRIMARY KEY (`clothNo`,`clothID`)
) ENGINE=InnoDB DEFAULT CHARSET=gb2312;
你当前的这个设计,就是clothNo会根据不同的clothID分别自增。