使用DQL语句查询数据

1.创建表

DROP TABLE IF EXISTS `tb_emp`;
CREATE TABLE `tb_emp`  (
  `emp_id` int(11) NOT NULL AUTO_INCREMENT,
  `emp_name` varchar(20) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `emp_sex` char(3) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `dept_id` int(11) NULL DEFAULT NULL,
  `salary` double(5, 1) NULL DEFAULT 4000.0,
  `emp_mail` varchar(30) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT 'DROP TABLE IF EXISTS `tb_emp`;
CREATE TA