条件为以逗号分隔的字段与 ID 相匹配的 MySQL JOIN 写法

CREATE TABLE `tbproduct` (
 `id` int NOT NULL AUTO_INCREMENT COMMENT '产品ID',
 `product_name` varchar(50) NULL COMMENT '产品名',
 `label_ids` varchar(50) NULL COMMENT '标签ID',
 PRIMARY KEY (`id`)
) ENGINE=InnoDB
DEFAULT CHARACTER SET=utf8
COMMENT='产品表';
CREATE TABLE `tblabel` (
 `id` int NOT NULL AUTO_INCREMENT COMMENT '标签ID',
 `label_name` varchar(50) NULL COMMENT '标签名',
 PRIMARY KEY (`id`)
) ENGINE=InnoDB
DEFAULT CHARACTER SET=utf8
COMMENT='标签表';

-- 插入标签
INSERT INTO `mumuzxdb`.`tblabel` (`label_name`) VALUES ('海外代购');
INSERT INTO `mumuzxdb`.`tblabel` (`label_name`) VALUES ('国产');
INSERT INTO `mumuzxdb`.`tblabel` (`label_name`) VALUES ('数码');
INSERT INTO `mumuzxdb`.`tblabel` (`label_name`) VALUES ('生鲜');
INSERT INTO `mumuzxdb`.`tblabel` (`label_name`) VALUES ('零食');
-- 插入产品
INSERT INTO `mumuzxdb`.`tbproduct` (`product_name`,`label_ids`) VALUES ('鲜桃花','2,4');
INSERT INTO `mumuzxdb`.`tbproduct` (`product_name`,`label_ids`) VALUES ('旺仔牛奶','2,5');
INSERT INTO `mumuzxdb`.`tbproduct` (`product_name`,`label_ids`) VALUES ('Iphone14','1,3');
INSERT INTO `mumuzxdb`.`tbproduct` (`product_name`,`label_ids`) VALUES ('雅诗兰黛','1');
INSERT INTO `mumuzxdb`.`tbproduct` (`product_name`,`label_ids`) VALUES ('红茶','1,2,5');

SELECT
    t1.id,
    t1.product_name,
    GROUP_CONCAT( t2.label_name SEPARATOR "-" ) AS label_names,
 t1.label_ids
FROM
    tbproduct t1
    LEFT JOIN `tblabel` t2 ON FIND_IN_SET( t2.id, t1.label_ids )
GROUP BY
    t1.`id`