2021-07-30 SQL Day13

一.SQL特性——事务管理

image.png

COMMIT 提交

将SQL语句的执行结果写入数据库表中

ROLLBACK 回退

撤销SQL语句的执行结果

SAVEPOINT 保留点

时间点的备份，可以对其发布回退

MySQL 代码

D:\mysql\mysql80\mysql -uroot -p
Enter password: ***
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 15
Server version: 8.0.23 MySQL Community Server - GPL

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> USE sqllearning
Database changed
mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
+--------+---------+---------+------+------------+------------+
6 rows in set (0.01 sec)

mysql> INSERT INTO pet2 VALUES('test1', 'test', 'test', 'f', '20130901', NULL);
Query OK, 1 row affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
7 rows in set (0.00 sec)

mysql> ROLLBACK;
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
7 rows in set (0.00 sec)

mysql> SET AUTOCOMMIT = 0;
Query OK, 0 rows affected (0.00 sec)

mysql> INSERT INTO pet2 VALUES('test2', 'test', 'test', 'f', '20130901', NULL);
Query OK, 1 row affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
| test2  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
8 rows in set (0.00 sec)

mysql> ROLLBACK;
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
7 rows in set (0.00 sec)

mysql> COMMIT;
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
7 rows in set (0.00 sec)

mysql> SET AUTOCOMMIT = 1;
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
7 rows in set (0.00 sec)

mysql> INSERT INTO pet2 VALUES('test3', 'test', 'test', 'f', '20130901',NULL);
Query OK, 1 row affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
| test3  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
8 rows in set (0.00 sec)

mysql> ROLLBACK;
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
| test3  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
8 rows in set (0.00 sec)

mysql> BEGIN;
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
| test3  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
8 rows in set (0.00 sec)

mysql> DELETE FROM pet2 WHERE name = 'test3';
Query OK, 1 row affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
7 rows in set (0.00 sec)

mysql> ROLLBACK;
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
| test3  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
8 rows in set (0.00 sec)

mysql> SAVEPOINT sp1;
Query OK, 0 rows affected (0.00 sec)

mysql> DELETE FROM pet2 WHERE name = 'test3';
Query OK, 1 row affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
7 rows in set (0.00 sec)

mysql> SAVEPOINT sp2;
Query OK, 0 rows affected (0.00 sec)

mysql> INSERT INTO pet2 VALUES('test3','test','test','m','20180101',NULL);
Query OK, 1 row affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
| test3  | test    | test    | m    | 2018-01-01 | NULL       |
+--------+---------+---------+------+------------+------------+
8 rows in set (0.00 sec)

mysql> ROLLBACK TO sp1;
ERROR 1305 (42000): SAVEPOINT sp1 does not exist
mysql> INSERT INTO pet2 VALUES('test2', 'test', 'test', 'f', '20130901', NULL);
Query OK, 1 row affected (0.00 sec)

mysql> ROLLBACK TO sp1;
ERROR 1305 (42000): SAVEPOINT sp1 does not exist
mysql> ROLLBACK TO sp2;
ERROR 1305 (42000): SAVEPOINT sp2 does not exist
mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
| test3  | test    | test    | m    | 2018-01-01 | NULL       |
| test2  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
9 rows in set (0.00 sec)

mysql> DELETE FROM pet2 WHERE name = 'test3';
Query OK, 1 row affected (0.00 sec)

mysql>  SET AUTOCOMMIT = 0;
Query OK, 0 rows affected (0.00 sec)

mysql> SAVEPOINT sp1;
Query OK, 0 rows affected (0.00 sec)

mysql> INSERT INTO pet2 VALUES('test3','test','test','m','20190101',NULL);
Query OK, 1 row affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
| test2  | test    | test    | f    | 2013-09-01 | NULL       |
| test3  | test    | test    | m    | 2019-01-01 | NULL       |
+--------+---------+---------+------+------------+------------+
9 rows in set (0.00 sec)

mysql> ROLLBACK TO sp1;
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT * FROM pet2;
+--------+---------+---------+------+------------+------------+
| name   | owner   | species | sex  | birth      | death      |
+--------+---------+---------+------+------------+------------+
| Bowser | Diane   | dog     | m    | 1979-08-31 | 1995-07-29 |
| Buffy  | Har_old | dog     | f    | 1989-05-13 | 0000-00-00 |
| Chirpy | Gw%en   | bird    | f    | 1998-09-11 | NULL       |
| Claws  | Gw%%en  | cat     | m    | 1994-03-17 | NULL       |
| Fang   | Benny   | dog     | m    | 1990-08-27 | NULL       |
| Fluffy | Har_old | cat     | f    | 1993-02-04 | NULL       |
| test1  | test    | test    | f    | 2013-09-01 | NULL       |
| test2  | test    | test    | f    | 2013-09-01 | NULL       |
+--------+---------+---------+------+------------+------------+
8 rows in set (0.00 sec)

mysql> RELEASE SAVEPOINT sp1;
Query OK, 0 rows affected (0.00 sec)

mysql> COMMIT;
Query OK, 0 rows affected (0.00 sec)

二.SQL高级特性 —— 对字段的约束

image.png

三.SQL高级特性 —— 索引

image.png

四.数据库安全 —— DBA

image.png

五.课后作业

Q1：什么是事务？SQL 中为什么要使用事务管理？
答：成批执行的SQL语句叫作事务。
使用事务管理系统，可以确保成批执行的语句完全执行或完全不执行，并且可以通过点，控制语句执行进度。
使用事务管理，可以确保数据库信息的完整性。

Q2：请总结 SAVAPOINT 的用法。
答：
创建保留点：SAVEPOINT<保留点名>;
回退到保留点：ROLLBACK TO <保留点名>；
释放保留点：RELEASE SAVEPOINT<保留点名>；

Q3：请写出以下语句（Navicat 中操作）
1、从 milk_tea 表复制出 milk_tea2 表。
2、对 milk_tea 表的 in_price 列增加 UNIQUE 属性
3、开启一个事务管理
4、插入值 prod_id – ‘T1’, prod_name – ‘测试商品 1’，in_price – 88
5、插入值 prod_id – ‘T2’, prod_name – ‘测试商品 2’，in_price – 88
6、回退
7、重复 5 的操作

CREATE TABLE milk_tea2
AS
SELECT * FROM milk_tea;

SELECT * FROM milk_tea2;

ALTER TABLE milk_tea ADD CONSTRAINT UNIQUE(in_price);

BEGIN;

INSERT INTO milk_tea(prod_id, prod_name, in_price) VALUES('T1', '测试商品', 88);

SELECT * FROM milk_tea;

INSERT INTO milk_tea(prod_id, prod_name, in_price) VALUES('T2', '测试商品2', 88);

ROLLBACK;

SELECT * FROM milk_tea;

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2021-07-30 SQL Day13

一.SQL特性——事务管理

COMMIT 提交

ROLLBACK 回退

SAVEPOINT 保留点

MySQL 代码

二.SQL高级特性 —— 对字段的约束

三.SQL高级特性 —— 索引

四.数据库安全 —— DBA

五.课后作业

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