CREATE TABLE `producttype` (
`typeid` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(36) NOT NULL,
`parentid` int(11) DEFAULT NULL,
PRIMARY KEY (`typeid`),
) 单表分类表,parentid为父级类别,parentid也可能是二级三级如何查出一级分类下的所有类别
`typeid` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(36) NOT NULL,
`parentid` int(11) DEFAULT NULL,
PRIMARY KEY (`typeid`),
) 单表分类表,parentid为父级类别,parentid也可能是二级三级如何查出一级分类下的所有类别
SELECT *
FROM producttype
WHERE parentid = xxx
UNION ALL
SELECT self.*
FROM producttype self,
producttype parent
WHERE self.parentid = parent.id
AND parent.parentid = xxx
-> RETURNS varchar(1000)
-> BEGIN
-> DECLARE sTemp VARCHAR(1000);
-> DECLARE sTempChd VARCHAR(1000);
->
-> SET sTemp = '$';
-> SET sTempChd =cast(rootId as CHAR);
->
-> WHILE sTempChd is not null DO
-> SET sTemp = concat(sTemp,',',sTempChd);
-> SELECT group_concat(id) INTO sTempChd FROM treeNodes where FIND_IN_SET(pid,sTempChd)>0;
-> END WHILE;
-> RETURN sTemp;
-> END请问如何创建函数,我把代码复制到workbench里执行为何报错