一.mysql的连接：

header("Content-Type:text/html;charset=utf8");

$servername="localhost";

$username="root";

$password="password";

$link=new mysqli($servername,$username,$password);

if($link){

echo "创建成功";

}else{

echo "创建失败: “.$link->connect_error;

}

?>

二.创建数据库和删除数据库

header("Content-Type:text/html;charset=utf8");

$servername="localhost";

$username="root";

$password="password";

$link = mysqli_connect($servername,$username,$password);

if(!$link){

die("连接失败: ".mysqli_connect_error());

}

$sql = "CREATE DATABASE data2";

if(mysqli_query($link,$sql)){

echo "数据库创建成功";

} else{

echo "Error creating database: ".mysqli_error($link);

}

$sql = "drop database data2";

if($link->query($sql)){

echo "删除数据库成功";

}else {

echo "删除数据库失败: " . $link->error;

}

$link->close();

?>

创建：$sql = "create database 数据库名";

删除：$sql = "drop database 数据库名";

三 创建数据表和删除数据表

header("Content-Type:text/html;charset=utf8");

$servername="localhost";

$username="root";

$password="password";

$dbname="data";

$link = new mysqli($servername,$username,$password,$dbname);//注意这里需要添加所选的数据库

if($link->connect_error){

die("连接失败: ".$link->connect_error);

}

$sql = "CREATE TABLE MyGuests3(

id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,

firstname VARCHAR(30) NOT NULL,

lastname VARCHAR(30) NOT NULL,

email VARCHAR(50)

)";

if($link->query($sql)){

echo "数据表创建成功";

}else{

echo "创建数据表失败: ".$link->error;

}

$sql = "drop table myguests2,myguests3";

$link->select_db("data");if($link->query($sql)){

echo "删除数据表成功";

}else{

echo "删除数据表失败:".$link->error;

}

$link->close();

?>

创建数据表：$sql = "create table 数据表名(内容)”;

删除数据表:$sql = "drop table 数据表名";

四 插入数据

header("Content-Type:text/html;charset=utf8");

$servername="localhost";

$username="root";

$password="password";

$dbname="data";

$link=mysqli_connect($servername,$username,$password,$dbname);

if(!$link){

die("connection failed: ".mysqli_connect_error());

}

$sql ="insert into MyGuests2(firstname,lastname,email) values('John','Doe','john@example.com'),('Julie','Dooely','julie@example.com')";

if(mysqli_query($link,$sql)){

echo "插入数据成功";

}else{

echo "Error ". $sql . mysqli_error($link);

}

mysqli_close($link);

?>

插入方法:$sql = "insert into 数据表名(插入所含的内容) values(插入所需的内容1),(插入所需的内容2)";

预处理插入方法：

header("Content-Type:text/html;charset=utf8");

$servername="localhost";

$username="root";

$password="password";

$dbname="data";

$conn = new mysqli($servername, $username, $password, $dbname);

// 检测连接

if ($conn->connect_error) {

die("连接失败: " . $conn->connect_error);

}

// 预处理及绑定

$sql="INSERT INTO MyGuests (firstname, lastname, email) VALUES(?, ?, ?)";

$stmt = $conn->prepare($sql);

$stmt->bind_param("sss", $firstname, $lastname, $email);

// 设置参数并执行

$firstname = "John";

$lastname = "Doe";

$email = "john@example.com";

$stmt->execute();

$firstname = "Mary";

$lastname = "Moe";

$email = "mary@example.com";

$stmt->execute();

$firstname = "Julie";

$lastname = "Dooley";

$email = "julie@example.com";

$stmt->execute();

echo "新记录插入成功";

$stmt->close();

$conn->close();

?>

"INSERT INTO MyGuests (firstname, lastname, email) VALUES(?, ?, ?)";

这句中？号可以被替换为整型，字符串，浮点型和布尔值。

$stmt->bind_param("sss", $firstname, $lastname, $email);

sss代表即将输入三个字符串

i-整型 d-浮点型 s-字符串 b-布尔型

五 读取数据以及更新，删除数据

header("Content-Type:text/html;charset=utf8");

$servername="localhost";

$username="root";

$password="password";

$dbname="data";

$link = new mysqli($servername,$username,$password,$dbname);

if($link->connect_error){

die("连接失败: ".$link->connect_error());

}

$sql = "select id ,firstname , lastname from MyGuests";//选择所需读取的数据

$result = $link->query($sql);

if($result->num_rows>0){//获取结果行数

while($row = $result->fetch_assoc()){//若读取到结果，返回true值

echo "
id:" . $row["id"] . " - Name: ".$row["firstname"]. " ".$row["lastname"];

}

}else{

echo "0个结果";

}

$sql = "select *from MyGuests where firstname='Mary'";//根据内容进行选择

$result = $link ->query($sql);

while($row=$result->fetch_assoc()){

echo "
".$row["firstname"]." ".$row["lastname"];

}

$sql = "select *from MyGuests order by firstname asc , id desc";//对数据表进行排序，asc为增序，desc为减序

$result = $link->query($sql);

while($row=$result->fetch_assoc()){

echo "
id:" . $row["id"] . " - Name: ".$row["firstname"]. " ".$row["lastname"];

}

$sql = "update MyGuests set firstname='cool' where firstname='mary'";//更新数据

$link->query($sql);

$sql = "delete from MyGuests where firstname='cool'";//删除数据

$link ->query($sql);

$link->close();

?>