初探mysql

又是一个学过但没有用过的，现在只记得SELECT * FROM TABLE1了

首先下载安装Mysql，安装时会设置root账号密码。

打开command

Enter password: ***********
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 27
Server version: 8.0.15 MySQL Community Server - GPL

Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.

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>

SHOW DATABASES

mysql> SHOW DATABASES;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sakila             |
| sys                |
| test1              |
| world              |
+--------------------+
7 rows in set (0.11 sec)

CREATE DATABASE

mysql> CREATE DATABASE test
    -> ;
Query OK, 1 row affected (0.20 sec)

mysql> SHOW DATABASES;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sakila             |
| sys                |
| test               |
| test1              |
| world              |
+--------------------+
8 rows in set (0.00 sec)

USE DATABASE

mysql> USE test;
Database changed

TABLE

mysql> CREATE TABLE lang(name VARCHAR(20), handle VARCHAR(20));
Query OK, 0 rows affected (0.63 sec)

mysql> DESCRIBE lang;
+--------+-------------+------+-----+---------+-------+
| Field  | Type        | Null | Key | Default | Extra |
+--------+-------------+------+-----+---------+-------+
| name   | varchar(20) | YES  |     | NULL    |       |
| handle | varchar(20) | YES  |     | NULL    |       |
+--------+-------------+------+-----+---------+-------+
2 rows in set (0.00 sec)
mysql> INSERT INTO lang VALUES('C','handle');
Query OK, 1 row affected (0.11 sec)

mysql> SELECT *
    -> ;
ERROR 1096 (HY000): No tables used
mysql> SELECT * FROM lang;
+------+--------+
| name | handle |
+------+--------+
| C    | handle |
+------+--------+
1 row in set (0.00 sec)

mysql> INSERT INTO lang VALUES('C++','familar'),('Python','familar'),('JAVA','know');
Query OK, 3 rows affected (0.13 sec)
Records: 3  Duplicates: 0  Warnings: 0

mysql> SELECT * FROM lang;
+--------+---------+
| name   | handle  |
+--------+---------+
| C      | handle  |
| C++    | familar |
| Python | familar |
| JAVA   | know    |
+--------+---------+
4 rows in set (0.00 sec)

Typical SELECT

mysql> SELECT name FROM lang;
+--------+
| name   |
+--------+
| C      |
| C++    |
| Python |
| JAVA   |
+--------+
4 rows in set (0.00 sec)

mysql> SELECT * FROM lang WHERE name='C';
+------+--------+
| name | handle |
+------+--------+
| C    | handle |
+------+--------+
1 row in set (0.00 sec)