MySQL树形查询

Oracle的Start with…Connect By可以实现树的递归查询，mysql与Oracle不同，没有prior关键字，mysql需要自己写函数或存储过程来实现树的递归查询。

数据库表

DROP TABLE IF EXISTS category;
CREATE TABLE category (
categoryId int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT ‘商品类目id’,
categoryName varchar(64) NOT NULL COMMENT ‘商品类目名称’,
parentId int(10) unsigned DEFAULT NULL COMMENT ‘父级类目id’,
status enum(‘delete’,‘disabled’,‘enable’) NOT NULL DEFAULT ‘enable’ COMMENT ‘enabe-可用；disabled-不可用；delete-删除’,
PRIMARY KEY (categoryId),
KEY parentId (parentId),
CONSTRAINT category_ibfk_1 FOREIGN KEY (parentId) REFERENCES category (categoryId) ON DELETE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=888889 DEFAULT CHARSET=utf8;

---

– Records of category

---

INSERT INTO category VALUES (‘59’, ‘食品生鲜’, null, ‘enable’);
INSERT INTO category VALUES (‘75’, ‘茗茶’, ‘59’, ‘enable’);
INSERT INTO category VALUES (‘76’, ‘美妆个护’, null, ‘enable’);
INSERT INTO category VALUES (‘77’, ‘洗发护发’, ‘76’, ‘enable’);
INSERT INTO category VALUES (‘79’, ‘面膜’, ‘78’, ‘enable’);
INSERT INTO category VALUES (‘81’, ‘沐浴’, ‘82’, ‘enable’);
INSERT INTO category VALUES (‘82’, ‘身体护理’, ‘76’, ‘enable’);
INSERT INTO category VALUES (‘83’, ‘颈部’, ‘82’, ‘enable’);
INSERT INTO category VALUES (‘84’, ‘手足护品’, ‘82’, ‘enable’);
INSERT INTO category VALUES (‘87’, ‘牙膏/牙粉’, ‘80’, ‘enable’);
INSERT INTO category VALUES (‘90’, ‘香水彩妆’, ‘76’, ‘enable’);
INSERT INTO category VALUES (‘91’, ‘底妆’, ‘90’, ‘enable’);
INSERT INTO category VALUES (‘92’, ‘腮红’, ‘90’, ‘enable’);
INSERT INTO category VALUES (‘100’, ‘洗发’, ‘77’, ‘enable’);
INSERT INTO category VALUES (‘101’, ‘护发’, ‘77’, ‘enable’);

1. 根据分类ID查询包含该分类在内的所有父类ID

BEGIN
DECLARE sTemp VARCHAR(100);
DECLARE flag int(8);
SET sTemp='$';
SELECT count(1) INTO flag FROM category WHERE categoryId=cId;
	IF flag = 1 then
		WHILE cId IS NOT NULL DO 
			SET sTemp= CONCAT(sTemp,',',cId);
			SELECT parentId INTO cId FROM category WHERE categoryId=cId;
		END WHILE;	
	END IF;
	RETURN sTemp;
END

2. 根据分类ID查询包含该分类在内的所有子类ID

    CREATE FUNCTION getRecommendChildList(cId INT) 
    //cId为你要查询的节点。
     RETURNS VARCHAR(1000)  
     BEGIN
	DECLARE sTemp VARCHAR(100);
	DECLARE flag int(8);
	SET sTemp='$';
	SELECT count(1) INTO flag FROM category WHERE categoryId=cId;
	IF flag = 1 then
		WHILE cId IS NOT NULL DO 
			SET sTemp= CONCAT(sTemp,',',cId);
			SELECT parentId INTO cId FROM category WHERE categoryId=cId;
		END WHILE;	
	END IF;
	RETURN sTemp;
END