一直使用thinkphp或者laravel框架，越到后面越发现，这些框架占用太大了，最主要的是很多东西完全用不到，我就想为啥不能自己封装一个？想到就搞，这个是一个Db类，主要封装了MySQL的增删改查方法，使用起来类似thinkphp和laravel。

多的不说了，直接上代码：

<?phpclass Db
{protected static \PDO $connection; // 数据库连接protected static string $table; // 数据表名protected static array $wheres = []; // 查询条件protected static ?int $findId = null; // 查找的记录 IDprotected static bool $initialized = false; // 数据库连接是否已初始化// 确保数据库连接已建立protected static function ensureConnection(){if (!self::$initialized) {self::$connection = new \PDO("mysql:host=localhost;dbname=数据库名称", "数据库用户名", "数据库密码");self::$initialized = true;}}// 设置数据表名public static function table(string $table): self{self::ensureConnection();self::$table = $table;return new self();}// 设置查询条件public static function where(string $column, string $operator, $value): self{self::$wheres[] = compact('column', 'operator', 'value');return new self();}// 根据 ID 查询记录public static function find(int $id): array{self::ensureConnection();$query = "SELECT * FROM " . self::$table . " WHERE id = :id";$statement = self::$connection->prepare($query);$statement->execute([':id' => $id]);return $statement->fetch(\PDO::FETCH_ASSOC);}// 查询符合条件的记录public static function get(): array{self::ensureConnection();$query = "SELECT * FROM " . self::$table;if (!empty(self::$wheres)) {$query .= " WHERE ";foreach (self::$wheres as $where) {$query .= "{$where['column']} {$where['operator']} '{$where['value']}' AND ";}$query = rtrim($query, " AND ");}$statement = self::$connection->prepare($query);$statement->execute();return $statement->fetchAll(\PDO::FETCH_ASSOC);}// 分页查询public static function paginate(int $page = 1, int $perPage = 10): array{self::ensureConnection();$offset = ($page - 1) * $perPage;$query = "SELECT COUNT(*) as count FROM " . self::$table;if (!empty(self::$wheres)) {$query .= " WHERE ";foreach (self::$wheres as $where) {$query .= "{$where['column']} {$where['operator']} '{$where['value']}' AND ";}$query = rtrim($query, " AND ");}$statement = self::$connection->prepare($query);$statement->execute();$totalResults = $statement->fetchColumn();$query = "SELECT * FROM " . self::$table;if (!empty(self::$wheres)) {$query .= " WHERE ";foreach (self::$wheres as $where) {$query .= "{$where['column']} {$where['operator']} '{$where['value']}' AND ";}$query = rtrim($query, " AND ");}$query .= " LIMIT $perPage OFFSET $offset";$statement = self::$connection->prepare($query);$statement->execute();$results = $statement->fetchAll(\PDO::FETCH_ASSOC);$totalPages = ceil($totalResults / $perPage);return ['data' => $results,'total' => $totalResults,'perPage' => $perPage,'currentPage' => $page,'totalPages' => $totalPages,];}// 插入数据public static function insert(array $data): bool{self::ensureConnection();$columns = implode(', ', array_keys($data));$placeholders = implode(', ', array_fill(0, count($data), '?'));$values = array_values($data);$query = "INSERT INTO " . self::$table . " ($columns) VALUES ($placeholders)";$statement = self::$connection->prepare($query);return $statement->execute($values);}// 更新数据public static function update(array $data, int $id): bool{self::ensureConnection();$updates = [];foreach ($data as $column => $value) {$updates[] = "$column = ?";}$setClause = implode(', ', $updates);$query = "UPDATE " . self::$table . " SET $setClause WHERE id = ?";$values = array_values($data);$values[] = $id;$statement = self::$connection->prepare($query);return $statement->execute($values);}// 删除数据public static function delete(int $id): bool{self::ensureConnection();$query = "DELETE FROM " . self::$table . " WHERE id = ?";$statement = self::$connection->prepare($query);return $statement->execute([$id]);}
}

使用方法：

假设有一个名为 users 的数据表

1.插入一条数据

Db::table('users')->insert(['name' => 'John', 'age' => 30]);

2.查询 ID 为 1 的记录

$result = Db::table('users')->find(1);
var_dump($result); // 输出查询结果

3.更新 ID 为 1 的记录

Db::table('users')->update(['age' => 35], 1);

4.查询年龄大于 30 的用户，并分页显示

$users = Db::table('users')->where('age', '>', 30)->paginate(1, 10);
var_dump($users); // 输出分页结果

5.删除 ID 为 1 的记录

Db::table('users')->delete(1);

大概就是这样了，实现了简单的增删改查，如果不够的可以自己添加一些代码