PHP连接并操作数据库_代码007(未授权)

本文介绍: PHP连接并操作数据库，实验，php代码。

（如果有环境请直接跳过，阅读下面的操作）

在Linux中进行PHP和数据库的环境搭建（适用于CentOS-7.0版本或以上）,以下操作全部是在root用户中操作，普通用户中记得命令前加入sudo进行提权后进行操作。

yum install -y mariadb-server
systemctl restart mariadb
systemctl enable mariadb

可以用这个手动设置密码，防止空密码登录

MariaDB [(none)]> use mysql;  
MariaDB [mysql]> UPDATE user SET password=password('newpassword') WHERE user='root';  
MariaDB [mysql]> flush privileges;   
MariaDB [mysql]> exit;

如果觉得上面的有点麻烦，就用下面的这个方法，下面的方法不行就用上面的这个

mysql_secure_insatallation

第一步，程序询问你的数据库root密码，但是我们是初次配置，root密码并不存在，这里直接安一下回车就行

Enter current password for root (enter for none): 【这里直接回车】

第二步，程序询问是否需要设置root密码

Set root password? [Y/n] y【这里输入“y”】
New password: 【这里输入“数据库密码”】
Re-enter new password: 【这里输入“数据库密码”】

Remove anonymous users? [Y/n] y【这里输入“y”】

Disallow root login remotely? [Y/n] n【这里输入“n”】

Remove test database and access to it? [Y/n] y【这里输入“y”】

Reload privilege tables now? [Y/n] y【这里输入“y”】

看到Thanks for using MariaDB!即配置完毕，可正常使用。

yum install -y php php-mysql php-gd php-imap php-ldap php-odbc php-pear php-xml php-xmlrpc

systemctl restart httpd
systemctl enable httpd

cd /var/www/html/

<?php
$servername="localhost";
$username="username";	# 这里写数据库用户
$password="password";	# 这里写数据库密码
$conn=new mysqli($servername,$username,$password);
if($conn->connect_error){
    die("连接失败:".$conn->connect_error);
}
else{
    echo "连接成功";
}
$conn->close();

<?php
$servername="localhost";
$username="username";
$password="password";
$conn=new mysqli($servername,$username,$password);
if($conn->connect_error){
    die("连接失败:".$conn->connect_error);
}
else{
    echo "连接成功";
}
$sql="create database mydb";	# 这里写创建数据库的语句
if ($conn->query($sql)===TRUE){
    echo "<br>数据库创建成功";
}else{
    echo "<br>创建失败:".$conn->error;
}

<?php
$hostname="localhost";
$username="username";
$password="password";
$database="mydb";	# 自己创建的数据库名
$conn=new mysqli($hostname,$username,$password,$database);
  if($conn->connect_error)
   {
     die("数据库连接失败:".$conn->connect_error);
   }
  echo "数据库连接成功";
$sql1="CREATE TABLE MyGuests (
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY, 
firstname VARCHAR(30) NOT NULL,
lastname VARCHAR(30) NOT NULL,
email VARCHAR(50),
reg_date TIMESTAMP)";
if($conn->query($sql1)===TRUE){
    echo "<br>创建表成功！";
}else{
    echo "<br>创建表错误:".$conn->error;
}
$conn->close();

<?php
$hostname="localhost";
$username="username";
$password="password";
$database="mydb";
$conn = mysqli_connect($servername, $username, $password, $dbname);
if (!$conn) {
    die("数据库连接成功: " . mysqli_connect_error());
}else {
    echo "数据库连接成功！";
}
$sql = "INSERT INTO MyGuests (firstname, lastname, email)
VALUES ('erhetest', 'grouptest', 'erhetest@group.com');";
if (mysqli_multi_query($conn, $sql)) {
    echo "<br>新记录插入成功";
} else {
    echo "<br>新记录插入失败: " . $sql . "<br>" . mysqli_error($conn);
}
mysqli_close($conn);

<?php
$hostname="localhost";
$username="username";
$password="password";
$database="mydb";
$conn = mysqli_connect($servername, $username, $password, $dbname);
if (!$conn) {
    die("数据库连接失败: " . mysqli_connect_error());
}else {
    echo "数据库连接成功！";
}
$sql = "INSERT INTO MyGuests (firstname, lastname, email)
VALUES ('erhe', 'group', 'erhe@group.com');";
$sql .= "INSERT INTO MyGuests (firstname, lastname, email)
VALUES ('erhe2', 'group2', 'erhe2@group2.com');";
$sql .= "INSERT INTO MyGuests (firstname, lastname, email)
VALUES ('welcome', 'to', 'welcome@erhe.group')";
if (mysqli_multi_query($conn, $sql)) {
    echo "<br>新记录插入成功";
} else {
    echo "<br>新记录插入失败: " . $sql . "<br>" . mysqli_error($conn);
}
mysqli_close($conn);

<?php
$hostname="localhost";
$username="username";
$password="password";
$database="mydb";
 $conn=new mysqli($hostname,$username,$password,$database);
  if($conn->connect_error)
   {
     die("数据库连接失败:".$conn->connect_error);
   }
  echo "数据库连接成功";
$sql = "SELECT id, firstname, lastname,email FROM MyGuests";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // 输出数据
    while($row = $result->fetch_assoc()) {
       foreach($row as $keyname=>$keyvalue)
         {
            echo $keyname."=>".$keyvalue;
            echo "<br>";
         }
       //echo "id: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>";
    }
} else {
    echo "0 结果";
}
$conn->close();

<?php
$hostname="localhost";
$username="username";
$password="password";
$database="mydb";
 $conn=new mysqli($hostname,$username,$password,$database);
  if($conn->connect_error)
   {
     die("连接数据库失败:".$conn->connect_error);
   }
  echo "连接数据库成功";
$sql="UPDATE MyGuests SET email='shuaishuai@163.com' WHERE id=1";
if ($conn->query($sql) === TRUE) {
    echo "<br>修改成功";
} else {
    echo "<br>修改成功:" . $sql . "<br>" . $conn->error;
}
$conn->close();

<?php
$hostname="localhost";
$username="username";
$password="password";
$database="mydb";
 $conn=new mysqli($hostname,$username,$password,$database);
  if($conn->connect_error)
   {
     die("连接数据库失败:".$conn->connect_error);
   }
  echo "连接数据库成功";
$sql="DELETE FROM MyGuests WHERE id='1'";
if ($conn->query($sql) === TRUE) {
    echo "<br>删除成功";
} else {
    echo "<br>删除失败:" . $sql . "<br>" . $conn->error;
}
$conn->close();