Files
4WDCSA.co.za/classes/DatabaseService.php
twotalesanimation 0143f5dd12 Add: DatabaseService class for abstracted database operations
- Created DatabaseService.php with full OOP database abstraction layer
- Methods: select(), selectOne(), insert(), update(), delete(), execute(), count(), exists()
- Transaction support: beginTransaction(), commit(), rollback()
- Error handling: getLastError(), getLastQuery() for debugging
- Type-safe parameter binding with prepared statements
- Updated connection.php to initialize $db service
- Available globally as $db variable after connection.php include
- Foundation for migrating from procedural $conn queries
2025-12-03 19:59:32 +02:00

321 lines
9.4 KiB
PHP

<?php
/**
* DatabaseService Class
*
* Provides a centralized database abstraction layer for all database operations.
* Enforces prepared statements, proper error handling, and type safety.
*
* @package 4WDCSA
* @version 1.0
*/
class DatabaseService {
private $conn;
private $lastError = null;
private $lastQuery = null;
/**
* Constructor - Initialize database connection
*
* @param mysqli $connection The MySQLi connection object
*/
public function __construct($connection) {
if (!$connection) {
throw new Exception("Database connection failed");
}
$this->conn = $connection;
}
/**
* Get the last error message
*
* @return string|null The last error or null if no error
*/
public function getLastError() {
return $this->lastError;
}
/**
* Get the last executed query
*
* @return string|null The last query or null
*/
public function getLastQuery() {
return $this->lastQuery;
}
/**
* Execute a SELECT query with parameter binding
*
* @param string $query SQL query with ? placeholders
* @param array $params Parameters to bind
* @param string $types Type specification string (e.g., "isi" for int, string, int)
* @return array|false Array of results or false on error
*/
public function select($query, $params = [], $types = "") {
try {
$this->lastQuery = $query;
$stmt = $this->conn->prepare($query);
if (!$stmt) {
$this->lastError = "Prepare failed: " . $this->conn->error;
return false;
}
if (!empty($params) && !empty($types)) {
if (!$stmt->bind_param($types, ...$params)) {
$this->lastError = "Bind failed: " . $stmt->error;
return false;
}
}
if (!$stmt->execute()) {
$this->lastError = "Execute failed: " . $stmt->error;
return false;
}
$result = $stmt->get_result();
$data = [];
while ($row = $result->fetch_assoc()) {
$data[] = $row;
}
$stmt->close();
return $data;
} catch (Exception $e) {
$this->lastError = $e->getMessage();
return false;
}
}
/**
* Execute a SELECT query returning a single row
*
* @param string $query SQL query with ? placeholders
* @param array $params Parameters to bind
* @param string $types Type specification string
* @return array|false Single row as associative array or false
*/
public function selectOne($query, $params = [], $types = "") {
$results = $this->select($query, $params, $types);
return ($results && count($results) > 0) ? $results[0] : false;
}
/**
* Execute an INSERT query
*
* @param string $query SQL query with ? placeholders
* @param array $params Parameters to bind
* @param string $types Type specification string
* @return int|false Last insert ID or false on error
*/
public function insert($query, $params = [], $types = "") {
try {
$this->lastQuery = $query;
$stmt = $this->conn->prepare($query);
if (!$stmt) {
$this->lastError = "Prepare failed: " . $this->conn->error;
return false;
}
if (!empty($params) && !empty($types)) {
if (!$stmt->bind_param($types, ...$params)) {
$this->lastError = "Bind failed: " . $stmt->error;
return false;
}
}
if (!$stmt->execute()) {
$this->lastError = "Execute failed: " . $stmt->error;
return false;
}
$insertId = $stmt->insert_id;
$stmt->close();
return $insertId;
} catch (Exception $e) {
$this->lastError = $e->getMessage();
return false;
}
}
/**
* Execute an UPDATE query
*
* @param string $query SQL query with ? placeholders
* @param array $params Parameters to bind
* @param string $types Type specification string
* @return int|false Number of affected rows or false on error
*/
public function update($query, $params = [], $types = "") {
try {
$this->lastQuery = $query;
$stmt = $this->conn->prepare($query);
if (!$stmt) {
$this->lastError = "Prepare failed: " . $this->conn->error;
return false;
}
if (!empty($params) && !empty($types)) {
if (!$stmt->bind_param($types, ...$params)) {
$this->lastError = "Bind failed: " . $stmt->error;
return false;
}
}
if (!$stmt->execute()) {
$this->lastError = "Execute failed: " . $stmt->error;
return false;
}
$affectedRows = $stmt->affected_rows;
$stmt->close();
return $affectedRows;
} catch (Exception $e) {
$this->lastError = $e->getMessage();
return false;
}
}
/**
* Execute a DELETE query
*
* @param string $query SQL query with ? placeholders
* @param array $params Parameters to bind
* @param string $types Type specification string
* @return int|false Number of affected rows or false on error
*/
public function delete($query, $params = [], $types = "") {
return $this->update($query, $params, $types);
}
/**
* Execute an arbitrary query (for complex queries)
*
* @param string $query SQL query with ? placeholders
* @param array $params Parameters to bind
* @param string $types Type specification string
* @return mixed Query result or false on error
*/
public function execute($query, $params = [], $types = "") {
try {
$this->lastQuery = $query;
$stmt = $this->conn->prepare($query);
if (!$stmt) {
$this->lastError = "Prepare failed: " . $this->conn->error;
return false;
}
if (!empty($params) && !empty($types)) {
if (!$stmt->bind_param($types, ...$params)) {
$this->lastError = "Bind failed: " . $stmt->error;
return false;
}
}
if (!$stmt->execute()) {
$this->lastError = "Execute failed: " . $stmt->error;
return false;
}
$stmt->close();
return true;
} catch (Exception $e) {
$this->lastError = $e->getMessage();
return false;
}
}
/**
* Count rows matching a condition
*
* @param string $table Table name
* @param string $where WHERE clause (without WHERE keyword)
* @param array $params Parameters to bind
* @param string $types Type specification string
* @return int|false Row count or false on error
*/
public function count($table, $where = "1=1", $params = [], $types = "") {
$query = "SELECT COUNT(*) as count FROM {$table} WHERE {$where}";
$result = $this->selectOne($query, $params, $types);
return ($result) ? (int)$result['count'] : false;
}
/**
* Check if a record exists
*
* @param string $table Table name
* @param string $where WHERE clause (without WHERE keyword)
* @param array $params Parameters to bind
* @param string $types Type specification string
* @return bool True if record exists, false otherwise
*/
public function exists($table, $where, $params = [], $types = "") {
$count = $this->count($table, $where, $params, $types);
return ($count !== false && $count > 0);
}
/**
* Get the MySQLi connection object for advanced operations
*
* @return mysqli The MySQLi connection
*/
public function getConnection() {
return $this->conn;
}
/**
* Start a transaction
*
* @return bool Success status
*/
public function beginTransaction() {
try {
$this->conn->begin_transaction();
return true;
} catch (Exception $e) {
$this->lastError = $e->getMessage();
return false;
}
}
/**
* Commit a transaction
*
* @return bool Success status
*/
public function commit() {
try {
$this->conn->commit();
return true;
} catch (Exception $e) {
$this->lastError = $e->getMessage();
return false;
}
}
/**
* Rollback a transaction
*
* @return bool Success status
*/
public function rollback() {
try {
$this->conn->rollback();
return true;
} catch (Exception $e) {
$this->lastError = $e->getMessage();
return false;
}
}
}
?>