本文目录一览：
- 1、用php如何连接MySQL数据库，请写出代码。 急！！！
- 2、求PHP对MYSQL的简单操作代码！
- 3、帮忙解释下这Php连接Mysql的代码
- 4、php连接mysql代码怎么使用
- 5、php表单写入mysql数据库的代码
- 6、初学者 求PHP中MYSQL代码
用php如何连接MySQL数据库，请写出代码。 急！！！
$conn01 = mysql_connect("localhost",'root','123456');//root是帐号,123456是密码
$mycon=mysql_select_db('testdatabase',$conn01); //testdatabase是mysql数据库名
if($mycon){
echo("数据库连接成功");
}else{
echo("数据库连接失败");
}
mysql_query("set name utf8");//设置数据库连接字符集
求PHP对MYSQL的简单操作代码！
?php
$db=mysql_connect("host","dbuser","password"); //连接数据库服务器
mysql_select_db("dbname",$db); //选择数据库
mysql_query("set names gbk"); //统一字符集
//查询示例：
$sql="select * from tablename where condition"; //构造查询语句
$result=mysql_query($sql,$db); //在先前选中的数据库中执行查询操作
//从查询结果集中取一行输出，直至所有行输出完毕
while($myrow=mysql_fetch_array($result))
{
print_r($myrow);
}
//插入示例：
$sql="insert into tablename values ('field1','field2',.......)"; //构造插入语句
$result=mysql_query($sql,$db); //执行插入
if ($result)
{
echo "插入成功！";
exit;
}
else
{
echo "插入失败！";
exit;
}
//修改、删除都是类似的，不再噜嗦
?
帮忙解释下这Php连接Mysql的代码
mysql_connect 是PHP连接MYSQL数据库的函数，返回一个连接标示符，参数依次是MYSQL的主机地址、用户名称、密码、默认数据库，一般如下调用：
mysql_connect('localhost','root');
mysql_query 是PHP执行MYSQL查询语句的函数，返回执行后的资源描述符，参数是SQL语句，一般如下使用：
$sql="select * from mysql.user";
$res=mysql_query($sql);
if ($res) {
while ($row=mysql_fetch_array($res)) echo "$row[host] $row[user]brn";
mysql_free_result($res);
} else echo "执行 $sql 错误：".mysql_error();
以后两个例子包含了常用的函数，利用这样的模板几乎可以编写任意MYSQL数据库操作的PHP程序。
php连接mysql代码怎么使用
1、首先，新建一个php_mysql.php的文件
2、其次，查看mysql服务是否打开，或者客户端的mysql能够正常打开。
鼠标右键电脑--》管理--》服务和应用程序--》服务--》找到mysql服务，看看是不是启用状态。
看看能不能打开客户端。
3、如果上面的可以了，那么就进入正题了，php连接mysql代码实例。
4、最后运行这个文件，看看运行结果吧。
php表单写入mysql数据库的代码
!--表单文件，拷入index.php--
!DOCTYPE html
html
head
style
label{display:inline-block;width:100px;margin-bottom:10px;}
/style
titleAdd students/title
/head
body
!-- 数据库用mysqli 面向过程调用方法--
form method="post" action="write2db.php"
!--数据库用mysqli 面向过程调用方法
form method="post" action="write2db_sqlio.php"
--
!--数据库用PDO调用方法
form method="post" action="write2db_pdo.php"
--
labelFirst Name/label
input type="text" name="first_name" /
br /
labelLast Name/label
input type="text" name="last_name" /
br /
labeldepartment/label
input type="text" name="department" /
br /
labelEmail/label
input type="text" name="email" /
br /
input type="submit" value="Add students"
/form
/body
/html
------------------------------
?php
//拷贝命名为write2db.php,数据库用mysqli 面向过程调用方法
//print_r($_POST);
// create a variable
$first_name=$_POST['first_name'];
$last_name=$_POST['last_name'];
$department=$_POST['department'];
$email=$_POST['email'];
//调试用
echo "Your input: ";
echo $first_name;
echo 'br /';
echo $last_name;
echo 'br /';
echo $department;
echo 'br /';
echo $email;
echo 'br /';
$servername = "localhost";
//Your database username and password
//$username = "username";
//$password = "password";
$username = "tester";
$password = "testerPassword";
//your database name
$dbname = "test";
$tablename ="student";
// Create connection
$connect = mysqli_connect($servername, $username, $password, $dbname);
if (!$connect) {
die("Connection failed: " . mysqli_connect_error());
}
//Execute the query
$sql="INSERT INTO $tablename (first_name,last_name,department,email)
VALUES('$first_name','$last_name','$department','$email')";
if (mysqli_query($connect, $sql)) {
echo "Hooray! New record is inserted to database successfully. Please check database.";
} else {
echo "Error: " . $sql . "br /" . mysqli_error($connect);
}
mysqli_close($connect);
?
?php
//拷贝命名为write2db_sqlio.php,数据库用mysqli 面向对象调用方法
//print_r($_POST);
// create a variable
$first_name=$_POST['first_name'];
$last_name=$_POST['last_name'];
$department=$_POST['department'];
$email=$_POST['email'];
//调试用
echo "Your input: ";
echo $first_name;
echo 'br /';
echo $last_name;
echo 'br /';
echo $department;
echo 'br /';
echo $email;
echo 'br /';
$servername = "localhost";
//Your database username and password
//$username = "username";
//$password = "password";
$username = "tester";
$password = "testerPassword";
//database name
$dbname = "test";
$tablename ="student";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn-connect_error) {
die("Connection failed: " . $conn-connect_error);
}
$sql="INSERT INTO $tablename (first_name,last_name,department,email)
VALUES('$first_name','$last_name','$department','$email')";
if ($conn-query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "br" . $conn-error;
}
$conn-close();
?
?php
//拷贝为文件write2db_pdo.php,数据库用PDO调用方法
//print_r($_POST);
a variable
$first_name=$_POST['first_name'];
$last_name=$_POST['last_name'];
$department=$_POST['department'];
$email=$_POST['email'];
//调试用
echo "Your input: ";
echo $first_name;
echo 'br /';
echo $last_name;
echo 'br /';
echo $department;
echo 'br /';
echo $email;
echo 'br /';
$servername = "localhost";
//Your database username and password
//$username = "username";
//$password = "password";
$username = "tester";
$password = "testerPassword";
//your database name
$dbname = "test";
$tablename ="student";
// Create connection
try {
$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
// set the PDO error mode to exception
$conn-setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$sql="INSERT INTO $tablename (first_name,last_name,department,email)
VALUES('$first_name','$last_name','$department','$email')";
// use exec()
$conn-exec($sql);
echo "New record created successfully";
}
catch(PDOException $e)
{
echo $sql . "br" . $e-getMessage();
}
$conn = null;
?
--创建数据库test, 将此文件存为test.sql 导入数据库，或者手动创建表结构
-- phpMyAdmin SQL Dump
-- version 4.7.4
--
--
-- Host: 127.0.0.1:3306
-- Generation Time: Mar 12, 2018 at 04:04 AM
-- Server version: 5.7.19
-- PHP Version: 7.1.9
SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO";
SET AUTOCOMMIT = 0;
START TRANSACTION;
SET time_zone = "+00:00";
/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8mb4 */;
--
-- Database: `test`
--
-- --------------------------------------------------------
--
-- Table structure for table `student`
--
DROP TABLE IF EXISTS `student`;
CREATE TABLE IF NOT EXISTS `student` (
`id` tinyint(3) UNSIGNED NOT NULL AUTO_INCREMENT,
`first_name` varchar(20) NOT NULL,
`last_name` varchar(20) NOT NULL,
`department` varchar(50) NOT NULL,
`email` varchar(50) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
--
-- Dumping data for table `student`
--
INSERT INTO `student` (`id`, `first_name`, `last_name`, `department`, `email`) VALUES
(1, 'first1', 'last1', 'cs', '1985@qq.com');
COMMIT;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
初学者 求PHP中MYSQL代码
1、如果没有把DD设置为常量， DD应该换成相应的数字或变量，假如stu_id为int型，则应为
?PHP
$sql = "select * from STUDENT where room = ( select room from STUDENT where stu_id = 1)";
?
或
?PHP
$sql = "select * from STUDENT where room = ( select room from STUDENT where stu_id = {$DD})";
?
或
?PHP
$sql = "select * from STUDENT where room = ( select room from STUDENT where stu_id = ".$DD.")";
?
如果stu_id为字符型，则sql应该为：
?PHP
$sql = "select * from STUDENT where room = ( select room from STUDENT where stu_id = '1')";
?
或
?PHP
$sql = "select * from STUDENT where room = ( select room from STUDENT where stu_id = '{$DD}')";
?
或
?PHP
$sql = "select * from STUDENT where room = ( select room from STUDENT where stu_id = '".$DD."')";
?
2、如果前面已经定义了 DD 常量，SQL语句中的DD应根据stu_id字段是否为字符型字段来决定是否用''包围起来