php与数据库的函数吗，php，分销处理函数

PHP 与数据库的函数

PHP 作为一种服务器脚本语言，常用于网站开发，而网站的核心数据通常是存储在数据库中的，因此PHP也提供了一系列的数据库操作函数，方便进行数据库的连接、查询、插入、更新等操作。

连接数据库

在PHP中，连接数据库有以下两种方式：

1. 使用MySQLi函数连接数据库

MySQLi是PHP内置的一个扩展，支持面向对象和面向过程的两种方式。

面向对象方式：

``` php

$servername = "localhost";

$username = "username";

$password = "password";

$dbname = "myDB";

// 创建连接

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

// 检测连接

if ($conn->connect_error)

{

die("连接失败: " . $conn->connect_error);

}

echo "连接成功";

```

面向过程方式：

``` php

$servername = "localhost";

$username = "username";

$password = "password";

$dbname = "myDB";

// 创建连接

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

// 检测连接

if (!$conn)

{

die("连接失败: " . mysqli_connect_error());

}

echo "连接成功";

```

2. 使用PDO函数连接数据库

PDO是PHP内置的一个扩展，提供了一个统一的接口，支持多种数据库类型，包括MySQL、SQLite、Oracle等。

``` php

$servername = "localhost";

$username = "username";

$password = "password";

$dbname = "myDB";

try

{

$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);

// 设置 PDO 错误模式为异常

$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

echo "连接成功";

}

catch(PDOException $e)

{

echo "连接失败: " . $e->getMessage();

}

```

查询数据

在连接数据库成功后，可以使用语句来查询数据库中的数据，并将结果返回到PHP中。

使用MySQLi函数查询数据：

``` php

$servername = "localhost";

$username = "username";

$password = "password";

$dbname = "myDB";

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

if ($conn->connect_error)

{

die("连接失败: " . $conn->connect_error);

}

$sql = "SELECT id, name, email FROM mytable";

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

if ($result->num_rows > 0)

{

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

{

echo "id: " . $row["id"]. " - Name: " . $row["name"]. " " . $row["email"]. "
";

}

}

else

{

echo "0 结果";

}

$conn->close();

```

使用PDO函数查询数据：

``` php

$servername = "localhost";

$username = "username";

$password = "password";

$dbname = "myDB";

try

{

$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);

$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

$stmt = $conn->prepare("SELECT id, name, email FROM mytable");

$stmt->execute();

$result = $stmt->setFetchMode(PDO::FETCH_ASSOC);

foreach($stmt->fetchAll() as $row)

{

echo "id: " . $row["id"]. " - Name: " . $row["name"]. " " . $row["email"]. "
";

}

}

catch(PDOException $e)

{

echo "Error: " . $e->getMessage();

}

$conn = null;

```

插入数据

使用MySQLi函数插入数据：

``` php

$servername = "localhost";

$username = "username";

$password = "password";

$dbname = "myDB";

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

if ($conn->connect_error)

{

die("连接失败: " . $conn->connect_error);

}

$sql = "INSERT INTO MyGuests (firstname, lastname, email) VALUES ('John', 'Doe', 'john@example.com')";

if ($conn->query($sql) === TRUE)

{

echo "新记录插入成功";

}

else

{

echo "Error: " . $sql . "
" . $conn->error;

}

$conn->close();

```

使用PDO函数插入数据：

``` php

$servername = "localhost";

$username = "username";

$password = "password";

$dbname = "myDB";

try

{

$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);

$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

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

VALUES ('John', 'Doe', 'john@example.com')";

$conn->exec($sql);

echo "新记录插入成功";

}

catch(PDOException $e)

{

echo $sql . "
" . $e->getMessage();

}

$conn = null;

```

更新数据

使用MySQLi函数更新数据：

``` php

$servername = "localhost";

$username = "username";

$password = "password";

$dbname = "myDB";

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

if ($conn->connect_error)

{

die("连接失败: " . $conn->connect_error);

}

$sql = "UPDATE MyGuests SET lastname='Doe' WHERE id=2";

if ($conn->query($sql) === TRUE)

{

echo "记录更新成功";

}

else

{

echo "Error updating record: " . $conn->error;

}

$conn->close();

```

使用PDO函数更新数据：

``` php

$servername = "localhost";

$username = "username";

$password = "password";

$dbname = "myDB";

try

{

$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);

$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

$sql = "UPDATE MyGuests SET lastname='Doe' WHERE id=2";

$conn->exec($sql);

echo "记录更新成功";

}

catch(PDOException $e)

{

echo $sql . "
" . $e->getMessage();

}

$conn = null;

```

综上所述，PHP与数据库的函数不仅包括了连接数据库、查询数据、插入数据、更新数据等操作，并且还支持多种不同的数据库类型。为了保证代码的安全性，我们应该对用户输入的数据进行过滤和验证，避免SQL注入等攻击。 如果你喜欢我们三七知识分享网站的文章， 欢迎您分享或收藏知识分享网站文章 欢迎您到我们的网站逛逛喔！https://www.ynyuzhu.com/