I just finished writing a flat-file DB class for PHP which supports selecting, updating, inserting and deleting.
I was wondering if there are any ways to make it faster or if I'm doing anything the wrong way.
<?php
class FlatDB {
private static $field_deliemeter = "\t";
private static $linebreak = "\n";
private static $table_extension = '.tsv';
public $table_name;
public $table_contents = array("FIELDS" => NULL, "RECORDS" => NULL);
/*
** This method creates a table
**
** @param string $table_name
**
** @example
** $db = new FlatDB;
** $db->createTable('Administrators');
**/
public function createTable($table_name, $table_fields) {
// Create the file
$tbl_name = $table_name.self::$table_extension;
$header = '';
foreach($table_fields as $field) {
$header .= $field.self::$field_deliemeter;
}
file_put_contents($tbl_name, $header);
}
/*
** This method opens a table for querying, editing, etc
**
** @param string $table_name
**
** @example
** $db = new FlatDB;
** $db->openTable('Test.csv');
**/
public function openTable($table_name) {
// Check if this table is found
$table_name = $table_name.self::$table_extension;
if(file_exists($table_name) === FALSE) throw new Exception('Table not found.');
// Set the table in a property
$this->table_name = $table_name;
// Get the fields
$table = file($this->table_name, FILE_IGNORE_NEW_LINES);
$table_fields = explode(self::$field_deliemeter, $table[0]);
unset($table[0]);
// Put all records in an array
$records = array();
$num = 0;
foreach($table as $record) {
$records_temp = explode(self::$field_deliemeter, $record);
$count = count($records_temp);
for($i = 0; $i < $count; $i++)
$records[$num][$table_fields[$i]] = $records_temp[$i];
$num++;
}
$this->table_contents['FIELDS'] = $table_fields;
$this->table_contents['RECORDS'] = $records;
}
/*
** This method returns fields selected by the user based on a where criteria
**
** @param array $select an array containing the fields the user wants to select, if he wants all fields he should use a *
** @param array $where an array which has field => value combinations
** @return array it returns an array containing the records
**
** @example
** $db = new FlatDB;
** $db->openTable('Test.csv');
** $select = array("id", "name", "group_id");
** $where = array("group_id" => 2);
** $db->getRecords($select, $where);
**/
public function getRecords($select, $where = array()) {
// Do some checks
if(is_array($select) === FALSE) throw new Exception('First argument must be an array');
if(is_array($where) === FALSE && isset($where)) throw new Exception('Second arguement must be an array');
if(empty($this->table_name) === TRUE) throw new Exception('There is no connection to a table opened.');
// If the array contains only one key which is a *, then select all fields
if($select[0] == '*') $select = $this->table_contents['FIELDS'];
// Check if the fieldnames in select are all found
foreach($select as $field_name)
if(in_array($field_name, $this->table_contents['FIELDS']) === FALSE) throw new Exception($field_name." is not found in the table.");
// Check if the fieldnames in where are all found
foreach($where as $field_name => $value)
if(in_array($field_name, $this->table_contents['FIELDS']) === FALSE) throw new Exception($field['name']." is not found in the table.");
// Find the record that the user queried in where
$user_records = $this->table_contents['RECORDS'];
if(isset($where)) {
foreach($where as $field => $value) {
foreach($this->table_contents['RECORDS'] as $key => $record) {
if($record[$field] != $value) {
unset($user_records[$key]);
}
}
}
}
// Preserve only the keys that the user asked for
$final_array = array();
$temp_fields = array_flip($select);
foreach($user_records as &$record) {
$final_array[] = array_intersect_key($record, $temp_fields);
}
return $final_array;
}
/*
** This method updates fields based on a criteria
**
** @param array $update an array containing the fields the user wants to update
** @param array $where an array which has field => value combinations which is the criteria
**
** @example
** $db = new FlatDB;
** $db->openTable('Test.csv');
** $update = array("group_id" => 1);
** $where = array("group_id" => 2);
** $db->updateRecords($update, $where);
**/
public function updateRecords($update, $where) {
// Check if the connection is opened
if(empty($this->table_name) === TRUE) throw new Exception('There is no connection to a table opened.');
// Check if each field in update and where are found
foreach($update as $field => $value)
if(in_array($field, $this->table_contents['FIELDS']) === FALSE) throw new Exception($field." is not found.");
foreach($where as $field => $value)
if(in_array($field, $this->table_contents['FIELDS']) === FALSE) throw new Exception($field." is not found.");
// Find the record that the user queried in where
$user_records = $this->table_contents['RECORDS'];
$preserved_records = array();
foreach($where as $field => $value) {
foreach($this->table_contents['RECORDS'] as $key => $record) {
if($record[$field] != $value) {
unset($user_records[$key]);
$preserved_records[$key] = $record;
}
}
}
// Update whatever needs updating
$user_records_temp = $user_records;
foreach($user_records_temp as $key => $record) {
foreach($update as $field => $value) {
$user_records[$key][$field] = $value;
}
}
// Merge the preserved records and the records that were updated, then sort them by their record number
$user_records += $preserved_records;
ksort($user_records, SORT_NUMERIC);
// Modify the property of the records and insert the new table
$this->table_contents['RECORDS'] = $user_records;
// Implode it so we can save it in a file
$final_array[] = implode(self::$field_deliemeter, $this->table_contents['FIELDS']);
foreach($user_records as $record)
$final_array[] = implode(self::$field_deliemeter, $record);
// Implode by linebreaks
$data = implode(self::$linebreak, $final_array);
// Save the file
file_put_contents($this->table_name, $data);
}
/*
** This method inserts a new record to the table
**
** @param array $insert an array containing field => value combinations
** @param array $where an array which has field => value combinations which is the criteria
**
** @example
** $db = new FlatDB;
** $db->openTable('Test.csv');
** $array = array("id" => 7, "name" => "Jack", "password" => "1234567", "group_id" => 2);
** $db->insertRecord($array);
**/
public function insertRecord($insert) {
if(is_array($insert) === FALSE) throw new Exception('The values need to be in an array');
if(empty($this->table_name) === TRUE) throw new Exception('You need to open a connection to a table first.');
// Check if each field in insert is found
foreach($insert as $field => $value)
if(in_array($field, $this->table_contents['FIELDS']) === FALSE) throw new Exception($field." is not found.");
// Build the new record
$newRecord = array();
foreach($this->table_contents['FIELDS'] as $field) {
if(isset($insert[$field])) $newRecord[$field] = $insert[$field];
else $newRecord[$field] = NULL;
}
// Add the new record to the pre-existing table and save it in the records
$records = $this->table_contents['RECORDS'];
$records[] = $newRecord;
$this->table_contents['RECORDS'] = $records;
// Format it for saving
$data = array();
$data[] = implode(self::$field_deliemeter, $this->table_contents['FIELDS']);
foreach($records as $record)
$data[] = implode(self::$field_deliemeter, $record);
// Implode by linebreaks
$data = implode(self::$linebreak, $data);
// Save in file
file_put_contents($this->table_name, $data);
}
/*
** This method deletes records from a table
**
** @param array $where an array which has field => value combinations which is the criteria
**
** @example
** $db = new FlatDB;
** $db->openTable('Test.csv');
** $where = array("group_id" => 3);
** $db->deleteRecords($where);
**/
public function deleteRecords($where) {
if(is_array($where) === FALSE) throw new Exception('The argument must be an array');
if(empty($this->table_name) === TRUE) throw new Exception('You need to open a connection to a database first.');
// Check if each field in insert is found
foreach($where as $field => $value)
if(in_array($field, $this->table_contents['FIELDS']) === FALSE) throw new Exception($field." is not found.");
// Find the records that match and delete them
$records = $this->table_contents['RECORDS'];
foreach($records as $key => $record) {
foreach($where as $field => $value) {
if($record[$field] == $value) unset($records[$key]);
}
}
// Save the records in the property
$this->table_contents['RECORDS'] = $records;
// Format it for saving
$data = array();
$data[] = implode(self::$field_deliemeter, $this->table_contents['FIELDS']);
foreach($records as $record)
$data[] = implode(self::$field_deliemeter, $record);
// Implode by linebreaks
$data = implode(self::$linebreak, $data);
// Save the file
file_put_contents($this->table_name, $data);
}
}
?>
