PHP实现增删改查的MySQLi数据库操作类

这是一个非常简单的使用PHP实现增删改查的MySQLi数据库操作类，以下是完整的代码及使用示例。

Database.php

<?php

class Database {
    private $host;
    private $user;
    private $password;
    private $database;
    private $connection;

    public function __construct($host, $user, $password, $database) {
        $this->host = $host;
        $this->user = $user;
        $this->password = $password;
        $this->database = $database;
        $this->connection = new mysqli($this->host, $this->user, $this->password, $this->database);
        if ($this->connection->connect_error) {
            die("Connection failed: " . $this->connection->connect_error);
        }
    }

    public function query($sql) {
        $result = $this->connection->query($sql);
        if (!$result) {
            die("Query failed: " . $this->connection->error);
        }
        return $result;
    }

    public function select($table, $fields, $conditions = "", $limit = "") {
        $sql = "SELECT " . $fields . " FROM " . $table;
        if (!empty($conditions)) {
            $sql .= " WHERE " . $conditions;
        }
        if (!empty($limit)) {
            $sql .= " ORDER BY " . $limit;
        }
        $result = $this->query($sql);
        $rows = array();
        while ($row = $result->fetch_assoc()) {
            $rows[] = $row;
        }
        return $rows;
    }

    public function insert($table, $data) {
        $keys = array();
        $values = array();
        foreach ($data as $key => $value) {
            $keys[] = $key;
            $values[] = "'" . $this->connection->real_escape_string($value) . "'";
        }
        $sql = "INSERT INTO " . $table . " (" . implode(", ", $keys) . ") VALUES (" . implode(", ", $values) . ")";
        return $this->query($sql);
    }

    public function update($table, $data, $conditions = "") {
        $set = array();
        foreach ($data as $key => $value) {
            $set[] = $key . "='" . $this->connection->real_escape_string($value) . "'";
        }
        $sql = "UPDATE " . $table . " SET " . implode(", ", $set);
        if (!empty($conditions)) {
            $sql .= " WHERE " . $conditions;
        }
        return $this->query($sql);
    }

    public function delete($table, $conditions = "") {
        $sql = "DELETE FROM " . $table;
        if (!empty($conditions)) {
            $sql .= " WHERE " . $conditions;
        }
        return $this->query($sql);
    }

    public function __destruct() {
        $this->connection->close();
    }
}

?>

Db.php

<?php

// MySQli数据库操作类
include 'Database.php';

// 数据库配置
$DbConfig = [
    'host' => 'xxx',
    'user' => 'xxx',
    'password' => 'xxx',
    'database' => 'xxx'
];

?>

使用

1. 创建Database.php文件并拷贝以上代码；

2. 创建Db.php文件并拷贝以上代码；修改配置信息，分别为数据库地址、数据库账号、密码、数据库名称；

3. 创建index.php文件；

4. 以上三个文件均在同一目录。

插入数据

<?php

// 引入配置
include './Db.php';

// 实例化
$db = new Database($DbConfig['host'], $DbConfig['user'], $DbConfig['password'], $DbConfig['database']);

$results = $db->insert('表名', array('字段名'=>'数据'));
// 例如：$results = $db->insert('users', array('username'=>'tanking','password'=>'123456'));

?>

删除数据

$results = $db->delete('test', 'id=1');
// 有两个参数，test是表名，id=1是条件

更新数据

$results = $db->update('test', array('user'=>'zhangsan','password'=>'888888'), 'id=1');
// 有三个参数，test是表名，array是修改的字段数据，id=1是条件

查询数据

$results = $db->select('test','user', 'id=1'); // 根据条件查询
// 有三个参数，test是表名，user是指定查询的字段，id=1是条件
// ---
// $results = $db->select('test','*','','id desc'); // desc排序
// 有四个参数，test是表名，*是查询所有字段，第三个参数为空就是不设置查询条件，id desc是排序
print_r($results);

执行原生语句

// 执行原生语句
$results = $db->query('SELECT * FROM test');

作者

TANKING