MySQL建立自关联表格举例

CREATE TABLE `tb_point_group_tree` (
`cgroup_id` int(11) NOT NULL DEFAULT ‘0‘,
`group_Id` int(11) NOT NULL AUTO_INCREMENT,
`company_Id` int(11) DEFAULT NULL,
`group_name` varchar(100) DEFAULT NULL,
`group_type_id` int(11) DEFAULT NULL COMMENT ‘分组类型：-1—普通分组，-2—用电类型，-3—区域用电，-4—生产流程，-5—重点设备‘,
`sub_parent_id` int(11) DEFAULT ‘0‘ COMMENT ‘分组类型子项编号为自关联的gruoup_Id，如果是父项，则该值为0‘,
PRIMARY KEY (`group_Id`),
KEY `FK_Reference_40` (`company_Id`) USING BTREE,
KEY `tb_sub_parent_id_FK` (`sub_parent_id`),
CONSTRAINT `tb_point_group_tree_ibfk_1` FOREIGN KEY (`company_Id`) REFERENCES `tb_customer_info` (`customer_Id`),
CONSTRAINT `tb_sub_parent_id_FK` FOREIGN KEY (`sub_parent_id`) REFERENCES `tb_point_group_tree` (`group_Id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=15 DEFAULT CHARSET=utf8 COMMENT=‘每个公司可以定义多个监测组，以方便管理‘;