Head First PHP&MySQL 学习笔记（二） —— Connect MySQL
MySQL
登录MySQL
$
mysql -h localhost -u root -p
-h : 服务器地址，如果在装在本机，在本机登录可直接使用localhost。
-u : 指定用户，MySQL在安装时会提示你输入管理员用户名和密码，使用这个用户名就可以。
-p : 需要输入密码，输入该命令后，会提示输入该用户的密码。
sunny@sunny-virtualbox:~$
mysql -h localhost -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 48
Server version: 5.5.37-0ubuntu0.14.04.1 (Ubuntu)
Copyright (c) 2000, 2014, 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;
+--------------------+
| Database |
+--------------------+
| information_schema |
| aliendatabase |
| mysql |
| performance_schema |
| phpmyadmin |
+--------------------+
5 rows in set (0.08 sec)
mysql>
use aliendatabase;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql>
select * from aliens_abduction;
+------------+-----------+------------------+----------+----------+--------------------------+----------------------------------------+--------------+--------------------------------------+-----------------------+
| first_name | last_name | when_it_happened | how_long | how_many | alien_description | what_they_did | fang_spotted | other | email |
+------------+-----------+------------------+----------+----------+--------------------------+----------------------------------------+--------------+--------------------------------------+-----------------------+
| Salley | Jones | 3 days ago | 1 day | four | green with six tentacles | We just talked and palyed with the dog | yes | I may have seen your dog, Contact me | [email protected] |
| maggie | xiang | 5 days ago | 2 days | 4 | 3 heads, 6 arms | Talk with them | yes | Contact me, Please! | [email protected] |
+------------+-----------+------------------+----------+----------+--------------------------+----------------------------------------+--------------+--------------------------------------+-----------------------+
2 rows in set (0.00 sec)
mysql>
创建数据库
mysql>
CREATE DATABASE aliendatabase;
mysql>
USE aliendatabase;
创建表
mysql>
CREATE TABLE
aliens_abduction (
first_name varchar(30),
last_name varchar(30),
when_it_happened varchar(30),
how_long varchar(30),
how_many varchar(30),
alien_description varchar(100),
what_they_did varchar(100),
fang_spotted varchar(10),
other varchar(100),
email varchar(50)
);
插入数据
mysql> INSERT INTO
aliens_abduction(first_name, last_name, when_it_happened, how_long, how_many, alien_description, what_they_did, fang_spotted, other, email) VALUES('Salley', 'Jones', '3 days ago', '1 day', 'four', 'green with six tentacles', 'We just talked and palyed with the dog', 'yes', 'I may have seen your dog, Contact me', '[email protected]')
MySQL in PHP
mysqli_connect() 连接MySQL数据库
mysqli_query() 执行一个查询（这里的查询不是指增、删、改、查中的“查”，而是泛指所有的操作）
mysqli_close() 关闭MySQL数据库连接
Tips：所有与MySQL交互的PHP函数都是以"mysqli_"开头的。（较早的一组与MySQL通信的PHP函数都是以"mysql_"开头的，没有"i"。这个"i"代表改进"improved"。现在更倾向于使用mysqli系列函数）
<?php
$first_name = $_POST['firstname'];
$last_name = $_POST['lastname'];
$when_it_happened = $_POST['whenithappened'];
$how_long = $_POST['howlong'];
$how_many = $_POST['howmany'];
$alien_description = $_POST['aliendescription'];
$what_they_did = $_POST['whattheydid'];
$fang_spotted = $_POST['fangspotted'];
$email = $_POST['email'];
$other = $_POST['other'];
$dbc = mysqli_connect('data.aliensabductedme.com', 'owen', 'aliensrool', 'aliendatabase')
or die('Error connecting to MySQL server.');
$query = "INSERT INTO aliens_abduction (first_name, last_name, when_it_happened, how_long, " .
"how_many, alien_description, what_they_did, fang_spotted, other, email) " .
"VALUES ('$first_name', '$last_name', '$when_it_happened', '$how_long', '$how_many', " .
"'$alien_description', '$what_they_did', '$fang_spotted', '$other', '$email')";
$result = mysqli_query($dbc, $query)
or die('Error querying database.');
mysqli_close($dbc);
?>
Note:
PHP中的SQL语句不以分号结束，这一点与PHP脚本语句不同。
PHP 支持 C，C++ 和 Unix Shell 风格（Perl 风格）的注释。
<?php
echo "This is a test"; // This is a one-line c++ style comment
/* This is a multi line comment
yet another line of comment */
echo "This is yet another test";
echo 'One Final Test'; # This is a one-line shell-style comment
?>