PHP文本连接数据库
准备工作
首先要打开mysql服务以及apache服务
在网页中输入127.0.0.1/phpmyadmin进入mysql图形化管理界面
新加一个名叫test的库，库里table1表，表里有id，username，password三个字段
连接数据库
在www目录下新建一个php，开始php连接数据库
connect_error){
die("error".$conn->connect_error);
}
echo "success";
?>
数据库增删改查
准备一条数据库语句，然后执行，最后输出结果
查
//查找语句,查找table1里id<3的数据
$sql = "SELECT * FROM table1 WHERE id < 3";
//执行sql语句，并且返回给变量$result
$result = $conn->query($sql);
//条件语句，如果$result不为空
if ($result->num_rows > 0)
{
//输出数据,fetch_accos()从结果集中取出一行作为关联数组
while ($row=$result->fetch_assoc()) {
echo $row['id'].'------'.$row['username'].'------'.$row['password']."
";
}
}else{
echo "0 结果";
}
?>
增
//插入数据
$sql = "INSERT INTO table1 (id,username,password) VALUES(4,'haha','123456')";
//===代表全等于 ==必须要求两边数据类型一致，否则会强制类型转换
if($conn->query($sql)===TRUE){
echo "success";
}else{
echo "error:".$conn->error;
}
删
$sql = "DELETE FROM table1 WHERE username='haha'";
if($conn->query($sql)===TRUE){
echo "success";
}else{
echo "error:".$conn->error;
}
改
$sql = "UPDATE table1 SET password='niu' WHERE username='xm'";
if($conn->query($sql)===TRUE){
echo "success";
}else{
echo "error:".$conn->error;
}
html和PHP结合起来美化网页
<html>
<head>
<title> db test </title>
</head>
<body>
<?php
$servername = "localhost";
$username = "root";
$password = "root";
$dbname = "test";
$conn = new mysqli($servername,$username,$password,$dbname);
if ($conn->connect_error){
die("error".$conn->connect_error);
}
$sql = "SELECT * FROM table1 WHERE id < 4";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
echo "<table border='1'>";
echo "<tr><th>id</th> <th>username</th> </tr>";
while ($row = $result->fetch_assoc()) {
echo "<tr>";
echo "<td>".$row['id']."</td>";
echo "<td>".$row['username']."</td>";
echo "</tr>";
}
echo "</table>";
}
$conn->close();
?>
</body>
</html>
