How to do robust PHP database modeling - php

Question

I am trying to figure out best practices for writing robust object oriented database models in PHP. I would like to use a data access layer and then have an abstract model class that my actual models would be able to extend. I was hoping to be able to encapsulate all basic CRUD functionality in these layers so I don't have to write lots of redundant code. I am having trouble finding tutorial on how to do this. Does anyone know of a tutorial or have example code on how to do this?

Answer 1

If you want to abstract this further to just make procedural calls to DbMgr.php above,
you can use the below code. This will help you develop project fast and anyone who doesn't have database knowledge can also use below methods to develop php mysql application.
CALL THIS FILE : DbMgrInterface.php
//Includes complete implementation of DB operations
require_once __DIR__.'/DbMgr.php';
$perform_Database_Operation = null; // Global variable to reuse the connection
$error_code = null; // Global variable holding the error_code for a transaction
function getDBConfig($config = ''){
$source = 'Func';
$type = 'mysql';
if(isset($config['source'])){
$source = $config['source'];
}
if( (strcasecmp("Func",$source) == 0) && (function_exists('get_DbConfig')) ) {
$config = get_DbConfig();
}
if(isset($config['type'])){
$type = $config['type'];
}
$config['dbType'] = strtolower($type);
$config['servername'] = $config['host'];
$config['Port'] = $config['port'];
$config['userName'] = $config['username'];
$config['passWord'] = $config['password'];
$config['DatabaseName'] = $config['database'];
return $config;
}
/**
Logic: If config array is passed to this method then definitely the new handle is required.
Else, If DBMgrHandle already exists then return the existing handle.
Else, get the default DB config, and instantiate a new DBMgr Handle.
*/
function DBMgr_Handle($config = '') {
global $perform_Database_Operation;
$className = 'DBMgr';
if(is_array($config)){
$config = getDBConfig($config);
if(strcasecmp($config['dbType'], 'mssql') == 0){
$className = 'SSRV';
}
$perform_Database_Operation = new $className($config);
return $perform_Database_Operation;
}
if(isset($perform_Database_Operation))
return $perform_Database_Operation;
$config = getDBConfig($config);
if(strcasecmp($config['dbType'], 'mssql') == 0){
$className = 'SSRV';
}
if(function_exists('getclassObject'))
$perform_Database_Operation = getclassObject($className, $config);
else
$perform_Database_Operation = new $className($config);
return $perform_Database_Operation;
}
/*=====================================================READ==============================================================*/
/*
* #access public
* #param associative_Array $readInput. Format is described below:
* array(
* 'Fields'=> 'Field1, Field2, Field3', //Mandatory
* 'Table'=> 'TableName', //Mandatory
* 'clause'=> 'FieldName = FieldValue', //optional
* 'order' => 'FieldName DESC' //optional
* )
clause refers exact/valid values as mysql query accepts.
clause is a condition to filter output. e.g. 'FieldName = DesiredValue' would return entries where FieldName has DesiredValue value only.
Order refers exact/valid values as mysql query accepts and is used to sort data selection. example value can be 'FieldName ASC' or 'FieldName DESC'.
* #param string $outputFormat. Values can be one of 'RESULT, NUM_ROWS, NUM_ARR, ASSOC', where ASSOC is default value.
* It defines whether the read should return 'mysql result resource/ Numbers of rows in result set / Numbered array / Associative array
* #param string $DataType. Value can only be 'JSON' else ''. Use this to get data set returned as json.
* #param string $keyField_Output. This can be a field name so that indexes of assoc array can be defined with value of the field passed.
*
* #return false, else 0(zero- for no corresponding entry), else output in described format.
* If mysql error is to be accessed, it is available with a aglobal variable $DB_OperationError
*/
function DB_Read($readInput, $outputFormat = "ASSOC", $DataType = "", $keyField_Output = '') {
$perform_Database_Operation = DBMgr_Handle();
return $perform_Database_Operation->Read($readInput, $outputFormat, $DataType, $keyField_Output);
}
/*=====================================================INSERT==============================================================*/
/*
* #access public
* #param associative_Array $insertInput. Format is described below:
* array(
* 'Table'=> 'TableName', //Mandatory
* 'Fields'=> array( //Mandatory
'FieldName1' =>Value1,
'FieldName2' =>Value2,
'FieldName_n'=>Value_n
)
* )
* So in above associative array the element refered by key 'Fields' is itself an associative array which would specify DbField and corresponding Value to be stored
* #return Inserted Id on success, else false on failure. If mysql error is to be accessed, it is available with a aglobal variable $DB_OperationError
*/
function DB_Insert($insertInput) {
$perform_Database_Operation = DBMgr_Handle();
return $perform_Database_Operation->Insert($insertInput);
}
/*=====================================================UPDATE==============================================================*/
/*
* #access public
* #param associative_Array $updateInput. Format is described below:
* array(
* 'Table'=> 'TableName', //Mandatory
* 'Fields'=> array( //Mandatory
'FieldName1' =>Value1,
'FieldName2' =>Value2,
'FieldName_n'=>Value_n
),
* 'clause'=> 'FieldName = FieldValue', //optional
* )
* So in above associative array the element refered by key 'Fields' is itself an associative array which would specify DbField and corresponding Value to be stored
* #return true on success, else false. If mysql error is to be accessed, it is available with a aglobal variable $DB_OperationError
*/
function DB_Update($updateInput) {
$perform_Database_Operation = DBMgr_Handle();
return $perform_Database_Operation->Update($updateInput);
}
/*=====================================================DELETE==============================================================*/
/*
* #access public
* #param associative_Array $deleteInput. Format is described below:
* array(
* 'Table'=> 'TableName', //Mandatory
* 'clause'=> 'FieldName = FieldValue', //OPTIONAL. But if not specified all the data from database would be deleted
* )
* So in above associative array the element refered by key 'Fields' is itself an associative array which would specify DbField and corresponding Value to be stored
* #return true on success, else false on failure. If mysql error is to be accessed, it is available with a aglobal variable $DB_OperationError
*/
function DB_Delete($deleteInput) {
$perform_Database_Operation = DBMgr_Handle();
return $perform_Database_Operation->Delete($deleteInput);
}
/*=====================================================RUN ABSOLUTE QUERY==============================================================*/
/*
* #access public
* #param Query as a string. Query can be of any type
* #param string $outputFormat. Values can be one of 'RESULT, NUM_ROWS, NUM_ARR, ASSOC', where ASSOC is default value.
* It defines whether the read should return 'mysql result resource/ Numbers of rows in result set / Numbered array / Associative array
* #param string $DataType. Value can only be 'JSON' else ''. Use this to get data set returned as json.
* #param string $keyField_Output. This can be a field name so that indexes of assoc array can be defined with value of the field passed.
*
* #return false, else 0(zero- for no corresponding entry), else output in described format. If mysql error is to be accessed, it is available with a aglobal variable $DB_OperationError
*/
function DB_Query($query, $outputFormat = "ASSOC", $DataType = "", $keyField_Output = '') {
$perform_Database_Operation = DBMgr_Handle();
return $perform_Database_Operation->Query($query, $outputFormat, $DataType, $keyField_Output);
}
/**
* The function makes a complete database dump of dump for selective tables, depending upon the TABLE_LIST. If TABLE_LIST is empty,
* a complete database dump is made, else dump for selective tables is carried out.
* #param unknown $ExportDBArray
* $ExportDBArray = array(
'DUMP_FILE_NAME' => 'dump.sql', // optional
'TABLE_LIST' => array( // optional
'Table1' => 'userinfo',
'Table2' => 'usageinfo'
)
);
* #return boolean
*/
function DB_ExportTable($ExportDBArray) {
$perform_Database_Operation = DBMgr_Handle();
return $perform_Database_Operation->Export($ExportDBArray);
}
/**
* The function imports SQL Dump from the given file path.
* #param unknown $ImportDBArray
* $ImportDBArray = array(
'COMPLETE_PATH' => __DIR__ . "\\database_dump.sql"
);
*/
function DB_ImportTable($ImportDBArray) {
$perform_Database_Operation = DBMgr_Handle();
return $perform_Database_Operation->Import($ImportDBArray);
}
/**
*
* #param unknown $multipleFieldsArray
* $multipleFieldsArray = array(
'TABLE_NAME' => 'userinfo',
'ID_LIST' => true ,
'FIELD_DETAILS' => array(
array('Username' => 'bjam123','Password' =>md5('password123'), 'UserType' => 1),
array('Username' => 'ppu12', 'Password' => md5('password1234'), 'UserType' => 2),
array('Username' => 'ppu13', 'Password' => md5('password12345'), 'UserType' => 3),
array('Username' => 'ppu14', 'Password' => md5('password123456'), 'UserType' => 4)
)
);
* #return array containing the insert_id
*/
function DB_InsertMultipleRows($multipleFieldsArray) {
$perform_Database_Operation = DBMgr_Handle();
return $perform_Database_Operation->InsertMR($multipleFieldsArray);
}
/**
* Call this function to perform MSSQL Server specific transactions
* #param unknown $fieldValueArray
* Format is described below:
* array(
* 'Fields'=> 'Field1, Field2, Field3', //Mandatory
* 'Table'=> 'TableName', //Mandatory
* 'clause'=> 'FieldName = FieldValue', //optional
* 'order' => 'FieldName DESC' //optional
* )
clause refers exact/valid values as mysql query accepts.
clause is a condition to filter output. e.g. 'FieldName = DesiredValue' would return entries where FieldName has DesiredValue value only.
Order refers exact/valid values as mysql query accepts and is used to sort data selection. example value can be 'FieldName ASC' or 'FieldName DESC'.
* #param unknown $operationType
* Possible Values - READ, INSERT, UPDATE, DELETE
* #param unknown $outputFormat
* Possible Values - ASSOC, NUM_ARR, NUM_ROWS
*/
function DB_SSRV_Transact($fieldValueArray, $operationType, $outputFormat) {
$perform_Database_Operation = SSRV_Handle();
$perform_Database_Operation->transact($fieldValueArray, $operation, $outputFormat);
}
/*=====================================================Close mysql connection or destroy mysqli object==============================================================*/
/*
* #access public
*/
function DB_Close()
{
$perform_Database_Operation = DBMgr_Handle();
$perform_Database_Operation->closeConnection();
global $perform_Database_Operation;
$perform_Database_Operation = null;
return;
}
?>

Answer 2

Something on these lines:
This is abstraction that uses mysqli extensions of php
CALL THIS FILE : DbMgr.php
<?php
class DBMgr{
private $mysql_Host, $Port, $userName, $passWord, $DatabaseName, $connection, $dbType;
//Constructor function to connect and select database.
/*
* The argument is a assoc array with possible following structure
* array(
* 'source' => 'value is a string. Possible values are Func/Coded', Default value is Func. For Func, the application must have already defined a functiobn name get_DbConfig, which will return assoc array with following structure,
* array(
* 'host' => '',
* 'port' => '',
* 'username' => '',
* 'password' => '',
* 'database' => '',
* 'type' => 'optional. The default value is mysql'
* );
* 'type' => 'mandatory/Required only for Coded Source' Default value is mysql. Other possible values are nssql,postgresql.
* 'host' => 'mandatory/Required only for Coded Source'
* 'port' => 'mandatory/Required only for Coded Source'
* 'username' => 'mandatory/Required only for Coded Source'
* 'password' => 'mandatory/Required only for Coded Source'
* 'database' => 'mandatory/Required only for Coded Source. This is the database name.'
* );
*
*/
function __construct($config)
{
$this->dbType = $config['dbType'];
$this->mysql_Host = $config['host'];
$this->Port = $config['port'];
$this->userName = $config['username'];
$this->passWord = $config['password'];
$this->DatabaseName = $config['database'];
$this->connect_SpecificDatabase();
}
function __destruct() {
$this->connection = null;
}
private function connect_SpecificDatabase(){
if(!isset($this->connection)) {
switch ($this->dbType) {
case 'mysql':
$db = new mysqli('p:'.$this->mysql_Host, $this->userName, $this->passWord, $this->DatabaseName, $this->Port); // Make a connection my MySQL
$this->connection = $db;
break;
case 'postgresql':
// Make a connection to PostgreSQL
$connectionString = "host = '".$this->mysql_Host."' port = '".$this->Port."' dbname = '".$this->DatabaseName."' user='".$this->userName."' password = '".$this->passWord."'";
$db = pg_connect($connection_string);
$this->connection = $db;
break;
}
}
else {
$db = $this->connection;
}
if (!$db)
return "Error: Connection failed '".$this->set_dbError()."'";
}
private function set_dbError($Query, &$DB_OperationError = '')
{
include_once __DIR__.'./../ErrorHandling.php';
$DB_OperationError = "";
global $error_code;
switch ($this->dbType) {
case 'mysql':
$DB_OperationError = mysqli_error($this->connection);
$error_code = mysqli_errno($this->connection);
break;
case 'mssql':
$DB_OperationError = mssql_get_last_message();
break;
case 'postgresql':
$DB_OperationError = pg_last_error($this->connection);
break;
}
ErrorLogging('query: --'.$Query.' -- '.'Error: --'.$DB_OperationError);
}
private function FieldValuePair_ToString($FieldValueArray,$onlyValueString=false)
{
$FieldsAsString = "";
foreach ($FieldValueArray as $FieldName => $value) {
if($FieldsAsString != "")
$FieldsAsString .= ', ';
/* if(strpos($value, '+') > 0 || strpos($value, '-') > 0)
$FieldsAsString .= $FieldName." = ".$value;
*/
if(strpos($value,'\'') !== false || strpos($value,'\"') !== false) {
$value = addslashes($value);
}
if($onlyValueString){
if($value != 'now()')
$FieldsAsString .= "'".$value."'";
else
$FieldsAsString .= $value;
}
else{
if($value != 'now()')
$FieldsAsString .= $FieldName." = '".$value."'";
else
$FieldsAsString .= $FieldName." = ".$value;
}
}
return $FieldsAsString;
}
public function Prepare_Output($output, $output_Format, $keyField_Output = '')
{
$output_Format = strtolower($output_Format); // Convert output_Format to lowercase
if(!is_object($output))
return $output;
elseif($output->num_rows == 0)
return 0;
switch($output_Format)
{
case 'result':
return $output;
break;
case 'num_rows':
return $output->num_rows;
break;
case 'num_arr':
while ($row = $output->fetch_array(MYSQLI_NUM)) {
$output_arr[] = $row;
}
return $output_arr;
break;
case 'assoc':
default:
while ($row = $output->fetch_assoc()) {
if($keyField_Output != '' && isset($row[$keyField_Output])){
$output_arr[strval($row[$keyField_Output])] = $row;
}
else
$output_arr[] = $row;
}
return $output_arr;
break;
}
}
private function Prepare_Query($input_array, $prepare_For)
{
$Query = "";
switch($prepare_For)
{
case 'READ':
if($input_array['Fields'] == "" || $input_array['Fields'] == NULL || $input_array['Table'] == "" || $input_array['Table'] == NULL)
return false;
$Query .= "SELECT ";
$Query .= $input_array['Fields'];
$Query .= " FROM ";
$Query .= $input_array['Table'];
if(isset($input_array['clause']) && $input_array['clause'] != "" && $input_array['clause'] !== NULL)
{
$Query .= " WHERE ";
$Query .= $input_array['clause'];
}
if(isset($input_array['order']) && $input_array['order'] != "" && $input_array['order'] !== NULL)
{
$Query .= " ORDER BY ";
$Query .= $input_array['order'];
}
break;
case 'INSERT':
if($input_array['Fields'] == "" || $input_array['Fields'] == NULL || $input_array['Table'] == "" || $input_array['Table'] == NULL)
return false;
$Query .= "INSERT INTO ";
$Query .= $input_array['Table'];
$Query .= " SET ";
$Query .= $this->FieldValuePair_ToString($input_array['Fields']);
break;
case 'UPDATE':
if($input_array['Fields'] == "" || $input_array['Fields'] == NULL || $input_array['Table'] == "" || $input_array['Table'] == NULL)
return false;
$Query .= "UPDATE ";
$Query .= $input_array['Table'];
$Query .= " SET ";
$Query .= $this->FieldValuePair_ToString($input_array['Fields']);
if(isset($input_array['clause']) && $input_array['clause'] != "" && $input_array['clause'] !== NULL)
{
$Query .= " WHERE ";
$Query .= $input_array['clause'];
}
break;
case 'DELETE':
if($input_array['Table'] == "" || $input_array['Table'] == NULL)
return false;
$Query .= "DELETE FROM ";
$Query .= $input_array['Table']."";
if($input_array['clause'] != "" && $input_array['clause'] !== NULL)
{
$Query .= " WHERE ";
$Query .= $input_array['clause'];
}
break;
case 'INSERT_MR':
$vstring = ""; // Field String
if(is_array($input_array)) {
$tableName = $input_array['TABLE_NAME'];
$input_array = $input_array['FIELD_ARRAY'];
for($i = 0 ;$i < count($input_array); $i++) {
$vstring .= "(" . $this->FieldValuePair_ToString($input_array[$i],true) . ")";
if(! ($i == (count($input_array) - 1))) $vstring .= ",";
}
// Column String
$column_string = implode("," , array_keys($input_array[0])); // Get the column names
$Query = "INSERT INTO ".$tableName." (" . $column_string . ") VALUES ".$vstring.";"; // Form Query String
}
break;
case 'IMPORT_DB':
if(is_array($input_array)) {
$completePathOfSQLFile = "\"" . $input_array['COMPLETE_PATH'];
$Query = "mysql --user" . $this->userName . " --password " . $this->DatabaseName . " < " . $completePathOfSQLFile;
}
break;
case 'EXPORT_DB':
if(is_array($input_array)) {
$TableArray = $input_array['TABLE_LIST'];
$dumpFileName = $input_array['DUMP_FILE_NAME'];
$dQuery = "mysqldump -h ".$this->mysql_Host." --port=".$this->Port." --user=".$this->userName." --password=".$this->passWord;
$dumpFilePath = __DIR__;
$dumpFileName = $dumpFileName == "" ? time().'mysqlDump.sql': $dumpFileName;
if(($TableArray == null) || count($TableArray) == 0 ) {
// Export all tables
$Query = $dQuery . " --databases ".$this->DatabaseName." > ".$dumpFilePath."\\".$dumpFileName;
} else {
$tableNames = "";
// Export selective tables
foreach($TableArray as $k => $k_value) {
$tableNames .= " " . $$TableArray[$k];
}
$Query = $dQuery . " " . $this->DatabaseNames." " . $tableNames . " > \"" . $dumpFilePath."\\".$dumpFileName."\"";
}
}
break;
}
return $Query;
}
public function Read($input_array, $outputFormat, $DataType = "", $keyField_Output = '')
{
$Query = $this->Prepare_Query($input_array, 'READ');
$output = "";
if(!$Query)
$output= 'INVALID';
else
{
$result = $this->connection->query($Query);
if (!$result)
{
$this->set_dbError($Query);
$output = false;
}
else
{
$output = $this->Prepare_Output($result, $outputFormat, $keyField_Output);
if( ($DataType != "") && (strcasecmp(strtolower($DataType) , 'as_json') == 0) )
$output = json_encode($output);
}
}
return $output;
}
public function Insert($input_array)
{
$Query = $this->Prepare_Query($input_array, 'INSERT');
$output = "";
if(!$Query)
$output= 'INVALID';
else
{
$result = $this->connection->query($Query);
if (!$result)
{
$this->set_dbError($Query);
$output = false;
}
else
{
$output = mysqli_insert_id($this->connection);
if(!$output)
return true;
}
}
return $output;
}
public function Update($input_array)
{
$Query = $this->Prepare_Query($input_array, 'UPDATE');
$output = "";
if(!$Query)
$output= 'INVALID';
else
{
$result = $this->connection->query($Query);
if (!$result)
{
$this->set_dbError($Query);
$output = false;
}
else
{
$output = true;
}
}
return $output;
}
public function Delete($input_array)
{
$Query = $this->Prepare_Query($input_array, 'DELETE');
$output = "";
if(!$Query)
$output= 'INVALID';
else
{
$result = $this->connection->query($Query);
if (!$result)
{
$this->set_dbError($Query);
$output = false;
}
else
{
$output = true;
}
}
return $output;
}
public function Query($Query, $outputFormat = 'ASSOC', $DataType = "", $keyField_Output = '')
{
$result = $this->connection->query($Query);
if (!$result)
{
$this->set_dbError($Query);
$output = false;
}
else
{
$output = $this->Prepare_Output($result, $outputFormat, $keyField_Output);
if($DataType != "")
$output = json_encode($output);
}
return $output;
}
public function Export($ExportDBArray) {
$Query = $this->Prepare_Query($input_array, 'EXPORT_DB');
$op = '';
$REtVal = '';
$query = 'dir';
$resultQuery = exec($query,$op,$REtVal);
if($resultQuery) return true;
else return false;
}
public function Import($ImportDBArray) {
$Query = $this->Prepare_Query($ImportDBArray, 'IMPORT_DB');
$resultQuery = exec($Query);
}
public function InsertMR($multipleFieldsArray) {
$tableName = $multipleFieldsArray['TABLE_NAME'];
$listOfID = $multipleFieldsArray['ID_LIST'];
$FieldsArray = $multipleFieldsArray['FIELD_DETAILS'];
$input_array = array('FIELD_ARRAY' => $FieldsArray, 'TABLE_NAME' => $tableName);
$Query = $this->Prepare_Query($input_array, 'INSERT_MR');
$result = $this->connection->query($Query); // Run Query
$output = array();
if (!$result) {
$this->set_dbError($Query);
} else {
$insert_id = mysqli_insert_id($this->connection);
if($listOfID) {
for($i=0; $i<count($FieldsArray); $i++) {
$output[$i] = $insert_id;
$insert_id++;
}
} else {
$output[0] = $insert_id;
}
}
return $output;
}
public function closeConnection() {
if(isset($this->connection)) {
mysqli_close($this->connection);
}
}
};
?>