删除重复数据不同id，且保留一条重复数据

-- 建表，插入测试数据

DROP TABLE IF EXISTS `table1`;
CREATE TABLE `table1` (
`id` int(11) NULL DEFAULT NULL,
`name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of table1
-- ----------------------------
INSERT INTO `table1` VALUES (1, 'A');
INSERT INTO `table1` VALUES (2, 'B');
INSERT INTO `table1` VALUES (3, 'C');
INSERT INTO `table1` VALUES (4, 'D');
INSERT INTO `table1` VALUES (5, 'E');
INSERT INTO `table1` VALUES (6, 'A');

SET FOREIGN_KEY_CHECKS = 1;

-- 所有数据
SELECT * FROM table1

-- 分组查询数据，查询不重复数据得id
SELECT min(id) FROM table1 GROUP BY name

-- 执行删除，若提示> 1093 -- You can't specify target table 'table1' for update in FROM clause
DELETE from table1 where id not in
(SELECT min(id) FROM table1 GROUP BY name)

-- 则使用以下sql ，套层查询，及查询结果
DELETE from table1 where id not in
(select * from (
SELECT min(id) as id FROM table1 GROUP BY name)a
)