Description:
select * from test where id = (select round(rand()*25 + 1));
run the sql,can not get only one row.
why?
How to repeat:
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for test
-- ----------------------------
DROP TABLE IF EXISTS `test`;
CREATE TABLE `test` (
`id` int NOT NULL AUTO_INCREMENT,
`name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL,
`uid` int NULL DEFAULT NULL,
`content` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 31 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
-- ----------------------------
-- Records of test
-- ----------------------------
INSERT INTO `test` VALUES (1, 'Jamie Black', 2, 'OYxqicEWUi');
INSERT INTO `test` VALUES (2, 'Xu Xiaoming', 6, 'VBKrVdvfWH');
INSERT INTO `test` VALUES (3, 'Yuen Chi Yuen', 24, '3J4u9lNfWV');
INSERT INTO `test` VALUES (4, 'Lau Wai Lam', 30, 'JQ8Hj779na');
INSERT INTO `test` VALUES (5, 'Xue Lu', 18, 'zGVHSz4HA4');
INSERT INTO `test` VALUES (6, 'Huang Rui', 13, 's2gvt0bbt9');
INSERT INTO `test` VALUES (7, 'Clara Coleman', 4, 'XJhXHRyZNa');
INSERT INTO `test` VALUES (8, 'Cao Jiehong', 28, 'h5UAClJEfS');
INSERT INTO `test` VALUES (9, 'Anna King', 26, 'GDIIJWwQYg');
INSERT INTO `test` VALUES (10, 'Cao Lan', 10, 'u4ZrFzzVA9');
INSERT INTO `test` VALUES (11, 'Lu Lu', 14, 'O3PvH90sZ0');
INSERT INTO `test` VALUES (12, 'Duan Xiuying', 1, '4QqPkwQuIU');
INSERT INTO `test` VALUES (13, 'Lau Sze Yu', 11, '3GoPut9BC4');
INSERT INTO `test` VALUES (14, 'Wu Zitao', 21, 'JdMog0rKvD');
INSERT INTO `test` VALUES (15, 'Cai Xiuying', 22, 'Xg9S4vol4E');
INSERT INTO `test` VALUES (16, 'Kwong Wai Man', 3, '7hB8cHGBJo');
INSERT INTO `test` VALUES (17, 'Liao Rui', 9, 'rypj6943Db');
INSERT INTO `test` VALUES (18, 'Luo Xiuying', 15, 'LHtvjuVzar');
INSERT INTO `test` VALUES (19, 'Deng Yuning', 16, 'R7wIEgAIZQ');
INSERT INTO `test` VALUES (20, 'Huang Yunxi', 27, '0TUIc4m9JP');
INSERT INTO `test` VALUES (21, 'Miguel Hawkins', 19, '5fJc06AN61');
INSERT INTO `test` VALUES (22, 'Mao Zitao', 8, 'l3NtTMkePs');
INSERT INTO `test` VALUES (23, 'Micheal Foster', 29, 'DjN5EfyyLt');
INSERT INTO `test` VALUES (24, 'Liao Anqi', 20, 'MgXUpBup9S');
INSERT INTO `test` VALUES (25, 'Walter Ferguson', 5, 'JUD7GXEI3D');
INSERT INTO `test` VALUES (26, 'Wei Rui', 17, 'X2dRVejypB');
INSERT INTO `test` VALUES (27, 'Jason Diaz', 23, 'nvauJRcgZ5');
INSERT INTO `test` VALUES (28, 'Tong Ho Yin', 25, 'U9ul58AqYa');
INSERT INTO `test` VALUES (29, 'Dai Kar Yan', 12, 'ruSvjfg8xA');
INSERT INTO `test` VALUES (30, 'Tang On Kay', 7, 'BbdLq6LBa1');
SET FOREIGN_KEY_CHECKS = 1;
select * from test where id = (select round(rand()*25 + 1));
