MySQL中DATE_FORMAT时间函数的使用小结

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ----------------------------
-- Table structure for userloginlog
-- ----------------------------
DROP TABLE IF EXISTS `userloginlog`;
CREATE TABLE `userloginlog`  (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `userId` bigint(20) NULL DEFAULT NULL,
  `isDelete` int(11) NULL DEFAULT 0,
  `createTime` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `updateTime` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP
  PRIMARY KEY (`id`) USING BTREE,
  INDEX `idx_userId_appId`(`userId` ASC, `appId` ASC) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 407701224 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = DYNAMIC;

SET FOREIGN_KEY_CHECKS = 1;

select count(*) from userloginlog u where DATE_FORMAT(u.createTime,'%Y') = '2024'

SELECT DATE_FORMAT(u.createTime,'%Y-%m') as month from userloginlog u

 SELECT DATE_FORMAT(u.createTime,'%m') as month, count(*) from userloginlog u where DATE_FORMAT(u.createTime,'%Y') = '2024'

GROUP BY month

SELECT DATE_FORMAT(u.createTime,'%Y-%m-%d')  from userloginlog u