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php实现增删改查

2026-04-02 19:37:17PHP

PHP 实现增删改查

数据库连接

使用 PDO（PHP Data Objects）连接数据库，确保安全性和兼容性。以下是一个基本的数据库连接示例：

<?php
$host = 'localhost';
$dbname = 'your_database';
$username = 'your_username';
$password = 'your_password';

try {
    $pdo = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e) {
    die("Connection failed: " . $e->getMessage());
}
?>

创建数据（Create）

通过预处理语句插入数据，防止 SQL 注入。

$sql = "INSERT INTO users (name, email) VALUES (:name, :email)";
$stmt = $pdo->prepare($sql);
$stmt->bindParam(':name', $name);
$stmt->bindParam(':email', $email);

$name = 'John Doe';
$email = 'john@example.com';
$stmt->execute();

读取数据（Read）

查询数据并显示结果。

$sql = "SELECT * FROM users";
$stmt = $pdo->query($sql);

while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
    echo "ID: " . $row['id'] . ", Name: " . $row['name'] . ", Email: " . $row['email'] . "<br>";
}

更新数据（Update）

通过预处理语句更新数据。

$sql = "UPDATE users SET name = :name WHERE id = :id";
$stmt = $pdo->prepare($sql);
$stmt->bindParam(':name', $name);
$stmt->bindParam(':id', $id);

$name = 'Jane Doe';
$id = 1;
$stmt->execute();

删除数据（Delete）

通过预处理语句删除数据。

$sql = "DELETE FROM users WHERE id = :id";
$stmt = $pdo->prepare($sql);
$stmt->bindParam(':id', $id);

$id = 1;
$stmt->execute();

错误处理

使用 try-catch 块捕获异常，确保代码的健壮性。

try {
    $stmt->execute();
} catch (PDOException $e) {
    echo "Error: " . $e->getMessage();
}

完整示例

以下是一个完整的增删改查示例：

php实现增删改查

<?php
$host = 'localhost';
$dbname = 'your_database';
$username = 'your_username';
$password = 'your_password';

try {
    $pdo = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    // Create
    $sql = "INSERT INTO users (name, email) VALUES (:name, :email)";
    $stmt = $pdo->prepare($sql);
    $stmt->bindParam(':name', $name);
    $stmt->bindParam(':email', $email);
    $name = 'John Doe';
    $email = 'john@example.com';
    $stmt->execute();

    // Read
    $sql = "SELECT * FROM users";
    $stmt = $pdo->query($sql);
    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
        echo "ID: " . $row['id'] . ", Name: " . $row['name'] . ", Email: " . $row['email'] . "<br>";
    }

    // Update
    $sql = "UPDATE users SET name = :name WHERE id = :id";
    $stmt = $pdo->prepare($sql);
    $stmt->bindParam(':name', $name);
    $stmt->bindParam(':id', $id);
    $name = 'Jane Doe';
    $id = 1;
    $stmt->execute();

    // Delete
    $sql = "DELETE FROM users WHERE id = :id";
    $stmt = $pdo->prepare($sql);
    $stmt->bindParam(':id', $id);
    $id = 1;
    $stmt->execute();
} catch (PDOException $e) {
    die("Error: " . $e->getMessage());
}
?>