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显示数据库
mysql> SHOW DATABASES;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sakila |
| sys |
| test |
| world |
+--------------------+
7 rows in set (0.00 sec)创建数据库
//创建了一个名为menageries的数据库
mysql> CREATE DATABASE menageries;
Query OK, 1 row affected (0.03 sec)切换数据库
//USE命令和QUIT命令相似，不需要以分号结尾，当然如果你加上也不会报错
mysql> USE test
Database changed创建表
//在menageries数据库中创建一张名为宠物的关系表
mysql> CREATE TABLE pet (name VARCHAR(20), owner VARCHAR(20),
-> species VARCHAR(20), sex CHAR(1), birth DATE, death DATE);
Query OK, 0 rows affected (0.42 sec)显示表
mysql> SHOW TABLES;
+----------------------+
| Tables_in_menageries |
+----------------------+
| pet |
+----------------------+
1 row in set (0.00 sec)显示表里面的详细信息
mysql> DESCRIBE pet;
+---------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+---------+-------------+------+-----+---------+-------+
| name | varchar(20) | YES | | NULL | |
| owner | varchar(20) | YES | | NULL | |
| species | varchar(20) | YES | | NULL | |
| sex | char(1) | YES | | NULL | |
| birth | date | YES | | NULL | |
| death | date | YES | | NULL | |
+---------+-------------+------+-----+---------+-------+
6 rows in set (0.00 sec)插入数据
1.通过命令行的方式插入
mysql> INSERT INTO pet
-> VALUES ('Fluffy', 'Harold', 'cat', 'f','1993-02-04', NULL);
Query OK, 1 row affected (0.13 sec)2.通过导入本地文件的方式插入
//文件内容，注意相邻的数据之间用TAB隔开，空数据用\N符号表示
Claws Gwen cat m 1994-03-17 \N
Buffy Harold dog f 1989-05-13 \N
Fang Benny dog m 1990-08-27 \N
Bowser Diane dog m 1979-08-31 1995-07-29
Chirpy Gwen bird F 1998-09-11 \N
Whistler Gwen bird \N 1997-12-09
Slim Benny snake m 1996-04-29 \N
//插入命令，注意Windows要加上下面一行命令，不然无法插入成功
mysql> LOAD DATA LOCAL INFILE 'E:/pet.txt' INTO TABLE pet
-> LINES TERMINATED BY '\r\n';
Query OK, 7 rows affected, 1 warning (0.08 sec)
Records: 7 Deleted: 0 Skipped: 0 Warnings: 1
//浏览插入的数据
mysql> SELECT * FROM pet;
+----------+--------+---------+------+------------+------------+
| name | owner | species | sex | birth | death |
+----------+--------+---------+------+------------+------------+
| Fluffy | Harold | cat | f | 1993-02-04 | NULL |
| Claws | Gwen | cat | m | 1994-03-17 | NULL |
| Buffy | Harold | dog | f | 1989-05-13 | NULL |
| Fang | Benny | dog | m | 1990-08-27 | NULL |
| Bowser | Diane | dog | m | 1979-08-31 | 1995-07-29 |
| Chirpy | Gwen | bird | F | 1998-09-11 | NULL |
| Whistler | Gwen | bird | NULL | 1997-12-09 | NULL |
| Slim | Benny | snake | m | 1996-04-29 | NULL |
+----------+--------+---------+------+------------+------------+
8 rows in set (0.00 sec)修改数据与删除数据
删除数据
//删除掉pet表中的全部数据
mysql> DELETE FROM pet;
Query OK, 8 rows affected (0.07 sec)
//删除后查询是否正确删除
mysql> SELECT * FROM pet;
Empty set (0.00 sec)
//查询知，delete只是删除了数据，并未删除关系表的整体结构
mysql> DESCRIBE pet;
+---------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+---------+-------------+------+-----+---------+-------+
| name | varchar(20) | YES | | NULL | |
| owner | varchar(20) | YES | | NULL | |
| species | varchar(20) | YES | | NULL | |
| sex | char(1) | YES | | NULL | |
| birth | date | YES | | NULL | |
| death | date | YES | | NULL | |
+---------+-------------+------+-----+---------+-------+
6 rows in set (0.04 sec)修改数据
//将Fang的出生日期改为2000-08-27
mysql> UPDATE pet SET birth = '2000-08-27' WHERE name = 'Fang';
Query OK, 1 row affected (0.11 sec)
Rows matched: 1 Changed: 1 Warnings: 0
//修改后表中的数据
mysql> SELECT * FROM pet;
+----------+--------+---------+------+------------+------------+
| name | owner | species | sex | birth | death |
+----------+--------+---------+------+------------+------------+
| Fluffy | Harold | cat | f | 1993-02-04 | NULL |
| Claws | Gwen | cat | m | 1994-03-17 | NULL |
| Buffy | Harold | dog | f | 1989-05-13 | NULL |
| Fang | Benny | dog | m | 2000-08-27 | NULL |
| Bowser | Diane | dog | m | 1979-08-31 | 1995-07-29 |
| Chirpy | Gwen | bird | F | 1998-09-11 | NULL |
| Whistler | Gwen | bird | NULL | 1997-12-09 | NULL |
| Slim | Benny | snake | m | 1996-04-29 | NULL |
+----------+--------+---------+------+------------+------------+
8 rows in set (0.00 sec)删除掉值为NULL的行
//删除掉性别未知的宠物的信息，注意这里的用法
mysql> DELETE FROM pet WHERE sex IS NULL;
Query OK, 1 row affected (0.08 sec)
//删除后
mysql> SELECT * FROM pet;
+--------+--------+---------+------+------------+------------+
| name | owner | species | sex | birth | death |
+--------+--------+---------+------+------------+------------+
| Fluffy | Harold | cat | f | 1993-02-04 | NULL |
| Claws | Gwen | cat | m | 1994-03-17 | NULL |
| Buffy | Harold | dog | f | 1989-05-13 | NULL |
| Fang | Benny | dog | m | 2000-08-27 | NULL |
| Bowser | Diane | dog | m | 1979-08-31 | 1995-07-29 |
| Chirpy | Gwen | bird | F | 1998-09-11 | NULL |
| Slim | Benny | snake | m | 1996-04-29 | NULL |
+--------+--------+---------+------+------------+------------+
7 rows in set (0.00 sec)