MySQL单表操作学习DDL_DML_DQL语句

1 创建数据库----DDL语句

CREATE TABLE `student` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '学号',
  `createDate` datetime DEFAULT NULL COMMENT '创建时间',
  `userName` varchar(20) DEFAULT NULL COMMENT '用户名',
  `pwd` varchar(36) DEFAULT NULL COMMENT '密码',
  `phone` varchar(11) DEFAULT NULL COMMENT '手机号',
  `age` tinyint(3) DEFAULT NULL COMMENT '年龄',
  `sex` char(2) DEFAULT NULL COMMENT '性别',
  `intrduce` varchar(255) DEFAULT NULL COMMENT '简介',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

2 插入数据----DML语句

INSERT INTO student
VALUES
	( 0, '2024-02-25 10:00:00', '盘古', '123456', '1234567', 255, '神', '12345678' );
INSERT INTO student
VALUES
	( 0, '2024-02-25 10:00:00', '女娲', '123456', '1234567', 255, '神', '12345678' );
INSERT INTO student
VALUES
	( 0, '2024-02-25 10:00:00', '黄帝', '123456', '1234567', 255, '神', '12345678' );
INSERT INTO student
VALUES
	( 0, '2024-02-25 10:00:00', '蚩尤', '123456', '1234567', 255, '神', '12345678' );
INSERT INTO student
VALUES
	( 0, '2024-02-25 10:00:00', '炎帝', '123456', '1234567', 255, '神', '12345678' );
INSERT INTO student
VALUES
	( 0, '2024-02-25 10:00:00', '精卫', '123456', '1234567', 255, '神', '12345678' );
INSERT INTO student
VALUES
	( 0, '2024-02-25 10:00:00', '神农', '123456', '1234567', 255, '神', '12345678' );
INSERT INTO student ( userName, age, intrduce )
VALUES
	( '仓颉', 222, '123456' );

3 基础查询----QDL语句

# 基础查询
SELECT * FROM student;
# 非空查询
SELECT userName as '姓名',age '年龄',introduce '介绍' FROM student where pwd is not null;
# 去重查询
SELECT DISTINCT sex '性别' FROM student;
# 分页查询
SELECT * FROM student LIMIT 6,3;
# 排序
SELECT * FROM student ORDER BY age asc;