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dom111 on 07/23/08

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Last Edited at 07/23/08 06:59pm

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PHP - Lightweight Database and Rowset class, ActiveRecord style functions

/ Published in: PHP

Been wanting to made one of these for a while and finally I got round to it.

For some examples please visit the post:
http://www.dom111.co.uk/blog/coding/db/8

Any comments suggestions appreciated.
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<?php
// DB - simple database wrapper
// The idea behind this database wrapper is to have a simple to use database wrapper that includes some useful
// commands to do some every day tasks.
//

class DB {
  // options
  public $enableMoreSearch = true; // disable this if any of your field names end with
  // _like, _before, _less_than, _after or _greater_than as this may cause problems
  // enables __call()s like find_by_name_like('dom') to match Dom, dom or DOM
  
  // variables
  public $c = null;
  public $db = null;
  public $table = null;
  public $id = 'id';
  
  private $engine = "mysql";
  private $host = "localhost";
  private $user = "root";
  private $pass = "";
  private $q = "";
  // private $db = "test";
  private $fields = array();

// __construct
  // sets up the connection to the mysql server and selects the database
  public function __construct($a = null) {
    if (is_array($a)) {
      $this->host = (isset($a['host'])) ? $a['host'] : $this->host;
      $this->user = (isset($a['user'])) ? $a['user'] : $this->host;
      $this->pass = (isset($a['pass']) && is_string($a['pass'])) ? $a['pass'] : $this->pass;
      $this->database = (isset($a['database'])) ? $a['database'] : $this->database;
      $this->table = (isset($a['table'])) ? $a['table'] : $this->table;

} elseif (is_string($a)) {
      if (preg_match("/^(mysql):\/\/([^:]+):(.*)@([a-z0-9\-\.]+):?(\d+)?\/([a-z0-9_\-]+)(\/([a-z0-9_\-]+))?\/?$/i", $a, $m)) {
        $this->engine = $m[1];
        $this->host   = $m[4];
        $this->user   = $m[2];
        $this->pass   = $m[3];
        $this->db     = $m[6];
        $this->table  = isset($m[8]) ? $m[8] : null;

} else {
        throw new Exception("DB Error! (Invalid connection details)");
      }
    }

if (!is_resource($this->c)) {
      if ($this->c = $this->_connect()) {
        if ($this->_select_db()) {
          return $this->c;

} else {
          throw new Exception("DB Error! (Could not select database)");
        }

} else {
        throw new Exception("DB Error! (Cound not connect to server)");
      }
    }
  }
  
  // __destruct
  // closes the connection
  public function __destruct() {
    return @$this->_close();
    // the @ is used because PHP shares mysql connections and if more than one
    // 'DB' instance is finished with at the same time, the second, third, etc
    // will produce errors, as the connection is already closed, the @ hides
    // any errors
  }

// __call
  // magic method to map unbound functions
  //   used for db->find_all_by_username("dom") etc
  public function __call($f, $a) {
    if (preg_match("/^find_(all_by|by)_([_a-zA-Z]\w*)$/", $f, $m)) {
      if ($m[1] == "by") {
        $array = false;

} elseif ($m[1] == "all_by") {
        $array = true;
      }

if (isset($a[1]) && is_array($a[1]) && isset($a[1]['table'])) {
        $t = $a[1]['table'];
      } else {
        $t = null;
      }

$fields = explode("_or_", $m[2]);

if (count($fields) == 1) {
        $fields = explode("_and_", $m[2]);
        $mode = "AND";
      } else {
        $mode = "OR";
      }

$find = array();
      
      if (count($fields) == count($a[0]) || (!is_array($a[0]) && count($fields) == 1)) {
        foreach ($fields as $i => $key) {
          if (is_array($a[0])) {
            $value = $a[0][$i];

} else {
            $value = $a[0];
          }
          
          if ($this->enableMoreSearch) {
            if (substr(strtolower($key), -5) == '_like') {
              $key = substr($key, 0, -5);
              $find[$key] = array('mode' => 'LIKE', 'value' => $value);
            } elseif (substr(strtolower($key), -13) == '_greater_than') {
              $key = substr($key, 0, -13);
              $find[$key] = array('mode' => '>', 'value' => $value);
            } elseif (substr(strtolower($key), -6) == '_after') {
              $key = substr($key, 0, -6);
              $find[$key] = array('mode' => '>', 'value' => $value);
            } elseif (substr(strtolower($key), -10) == '_less_than') {
              $key = substr($key, 0, -10);
              $find[$key] = array('mode' => '<', 'value' => $value);
            } elseif (substr(strtolower($key), -7) == '_before') {
              $key = substr($key, 0, -7);
              $find[$key] = array('mode' => '<', 'value' => $value);
            } else {
              $find[$key] = $value;
            }
          } else {
            $find[$key] = $value;
          }
        }
      } elseif (count($a) == count($fields)) {
        foreach ($fields as $i => $key) {
          $value = $a[$i];
          if ($this->enableMoreSearch) {
            if (substr(strtolower($key), -5) == '_like') {
              $key = substr($key, 0, -5);
              $find[$key] = array('mode' => 'LIKE', 'value' => $value);
            } elseif (substr(strtolower($key), -13) == '_greater_than') {
              $key = substr($key, 0, -13);
              $find[$key] = array('mode' => '>', 'value' => $value);
            } elseif (substr(strtolower($key), -6) == '_after') {
              $key = substr($key, 0, -6);
              $find[$key] = array('mode' => '>', 'value' => $value);
            } elseif (substr(strtolower($key), -10) == '_less_than') {
              $key = substr($key, 0, -10);
              $find[$key] = array('mode' => '<', 'value' => $value);
            } elseif (substr(strtolower($key), -7) == '_before') {
              $key = substr($key, 0, -7);
              $find[$key] = array('mode' => '<', 'value' => $value);
            } else {
              $find[$key] = $value;
            }
          } else {
            $find[$key] = $value;
          }
        }
      } else {
        throw new Exception('Number of fields and parameters don\'t match');
      }

return $this->find($find, array('table' => $t, 'mode' => $mode, 'array' => $array));

} elseif (preg_match("/^find_or_(initialize|create)_by_([_a-zA-Z]\w*)$/", $f, $m)) {
      
      $fields = explode("_and_", $m[2]);

$find = array();

if (count($fields) > 1 && is_array($a[0]) && count($fields) == count($a[0])) {
        foreach ($fields as $i => $key) {
          $value = $a[0][$i];
          $find[$key] = $value;
        }

} else {
        $find[$m[2]] = $a[0];
      }
      
      $check = $this->find($find, array('mode' => 'AND'));
      
      if (!empty($check)) {
        return $check;

} else {
        if ($m[1] == "create") {
          $this->create($find);
          
          return $this->find($this->lastId());

} elseif ($m[1] == "initialize") {
          $row = $this->_new();
          
          foreach ($find as $key => $value) {
            $row->$key = $value;
          }
          
          return $row;
        }
      }
    }

return false;
  }
  
  // _connect
  // simple function, maybe enable use of other database engines?
  private function _connect() {
    if ($this->engine == 'mysql') {
      return mysql_connect($this->host, $this->user, $this->pass);
    }
  }
    
  // _query
  // pretty simple again
  private function _query($q) {
    $this->q = $q;  // store the last query
    if ($this->engine == 'mysql') {
      return mysql_query($q, $this->c);
    }
  }
  
  // _num_rows
  // pretty simple again
  private function _num_rows($r) {
    if ($this->engine == 'mysql') {
      return mysql_num_rows($r);
    }
  }

// _select_db
  // pretty simple again
  private function _select_db() {
    if ($this->engine == 'mysql') {
      return mysql_select_db($this->db, $this->c);
    }
  }
  
  // _close
  // pretty simple again
  private function _close() {
    if ($this->engine == 'mysql') {
      return mysql_close($this->c);
    }
  }
  
  // _close
  // pretty simple again
  private function _auto_increment_id() {
    if ($this->engine == 'mysql') {
      return mysql_insert_id($this->c);
    }
  }

// _get
  // accepts a query string, or mysql resource and returns either and array
  // or an array of arrays depending on how many rows there are or if the
  // $array variable is true
  // private function _get($q, $array = false) {
  private function _get($q, $options = array()) {
    if (is_string($q)) {
      $q = $this->_query($q);
    }

if (!is_resource($q)) {
      return false;
    }

$r = $this->_num_rows($q);
    
    $options['array'] = !empty($options['array']) ? $options['array'] : false;
    $options['raw'] = isset($options['raw']) ? $options['raw'] : false;

if ($r) {
      // if we have a result...
      if ($r === 1 && !$options['array']) {
        // if there is only 1 row and array is not forced
        if ($this->engine == 'mysql') {
          // if we're using mysql...
          if ($options['raw']) {
            // if $options row == true, return the raw array, not a DB record object
            return mysql_fetch_assoc($q);

} else {
            return new DB_record($this, mysql_fetch_assoc($q));
          }
        }
      } else {
        // $options array == true or we have more than one row
        $a = array();

if ($this->engine == 'mysql') {
          // if we're using mysql
          while (($row = mysql_fetch_assoc($q)) != false) {
            // create a $row variable with the contetnts of the row
            if ($options['raw']) {
              $a[] = $row;

} else {
              $a[] = new DB_record($this, $row);
            }
          }
        }

return $a;
      }

} else {
      return false;
    }
  }
  
  public function query($q) {
    return $this->_query($q);
  }
  
  // find
  // builds a query to pass to get based on the variables passed
  // if $id is null it will use the current data->id, if $id is an array it
  // will match based on the array settings (correctly matching nulls), or
  // $id can just be a specified id
  // to match all users with a name like bob you could do:
  //   db->find(array('name' => array('mode' => 'LIKE', 'value' => '%bob%')), array('table' => 'users'));
  // to retrieve all rows from the current table you could do:
  //   db->find();
  // to retrieve a specific id you could do:
  //   db->find(123)
  public function find($id = null, $options = array()) {
    if (empty($options['table'])) {
      if (!empty($this->table)) {
        $options['table'] = $this->table;

} else {
        return false;
      }
    }

if ($id === null) {
      $options['array'] = isset($options['array']) ? $options['array'] : true;  // default behaviour to return an array

$q = "SELECT * FROM `{$options['table']}`";
      
      if (!empty($options['order']) && is_array($options['order'])) {
        $q .= ' ORDER BY ';
        $order = array();

foreach ($options['order'] as $field => $direction) {
          $direction = strtoupper($direction);

if ($direction !== 'ASC' && $direction !== 'DESC') {
            if ($field === 'RAND()') {
              $order[] = 'RAND()';

} else {
              $order[] .= "`{$field}`";
            }

} else {
            $order[] .= "`{$field}` {$direction}";
          }
        }
        $q .= implode(", ", $order);

} elseif (!empty($options['order']) && is_string($options['order'])) {
        $q .= " ORDER BY {$options['order']}";
      }

if (empty($options['offset']) && !empty($options['limit'])) {
        $q .= " LIMIT {$options['limit']}";

} elseif (!empty($options['offset']) && !empty($options['limit'])) {
        $q .= " LIMIT {$options['offset']},{$options['limit']}";
      }

$q .= ";";
      return $this->_get($q, $options);

} else {
      $options['array'] = isset($options['array']) ? $options['array'] : null;

$where = array();

if (is_array($id)) {
        foreach ($id as $k => $v) {
          if (is_array($v)) {
            $where[] = "`{$k}` {$v['mode']} '{$v['value']}'";

} elseif ($v === null) {
            $where[] = "ISNULL(`{$k}`)";

} else {
            $where[] = "`{$k}` = '{$v}'";
          }
        }
      } else {
        $where[] = "`{$this->id}` = '{$id}'";
      }
      
      if (isset($options['mode']) || ($options['mode'] != "OR" && $options['mode'] != "AND")) {
        $options['mode'] = 'OR';
      }

$q = "SELECT * FROM `{$options['table']}` WHERE ".implode(" {$options['mode']} ", $where);

if (isset($options['order']) && !empty($options['order']) && is_array($optinos['order'])) {
        $q .= ' ORDER BY ';
        $order = array();

foreach ($options['order'] as $field => $direction) {
          $direction = strtoupper($direction);

if ($direction !== 'ASC' || $direction !== 'DESC') {
            if ($field === 'RAND()') {
              $order[] = 'RAND()';

} else {
              $order[] .= "`{$field}`";
            }

} else {
            $order[] .= "`{$field}` {$direction}";
          }
        }
        $q .= implode(", ", $order);
      } elseif (isset($options['order']) && !empty($options['order']) && is_string($options['order'])) {
        $q .= " ORDER BY {$options['order']}";
      }

if (empty($options['offset']) && !empty($options['limit'])) {
        $q .= " LIMIT {$options['limit']}";

} elseif (!empty($options['offset']) && !empty($options['limit'])) {
        $q .= " LIMIT {$options['offset']},{$options['limit']}";
      }

$q .= ';';

return $this->_get($q, $options);
    }
  }
  
  // create
  // builds an INSERT query based on the variables passed
  // $data must be an associative array with indexes matching the field names
  // $table can be omitted and the current table will be used
  // to insert a new row to the current table you could do:
  //   db->create(array("name" => "bob", "password" => md5(md5("mytest")), "email" => "bob@email.com"));
  public function create($data = null, $options = array()) {
    if (empty($options['table'])) {
      if (!empty($this->table)) {
        $options['table'] = $this->table;

} else {
        return false;
      }
    }

if ($data !== null && is_array($data)) {
      $set = array();

foreach ($data as $k => $v) {
        if ($v === null) {
          $set[] = "`{$k}` = NULL";

} else {
          $set[] = "`{$k}` = '{$v}'";
        }
      }

$q = "INSERT INTO `{$options['table']}` SET ".implode(", ", $set).";";

$r = $this->_query($q);
      
      if ($r) {
        // if the query is successful return the create row
        return $this->find($this->lastId());
      } else {
        // else return false
        return false;
      }

} else {
      // data was null or not an array
      return false;
    }
  }
  
  // update
  // builds an UPDATE query based on the variables passed
  // $data must be an associative array with indexes matching the field names
  // $table and $id can be omitted for the current id/table to be used
  // to update the current record you could use:
  //   db->update(array("title" => "Cheese", "price" => 9.99));
  public function update($data, $id = null, $options = array()) {
    if (empty($options['table'])) {
      if (!empty($this->table)) {
        $options['table'] = $this->table;

} else {
        return false;
      }
    }
 
    if (is_array($data) && !empty($id)) {
      $set = array();
 
      foreach ($data as $k => $v) {
        if ($v === null) {
          $set[] = "`{$k}` = NULL";
 
        } else {
          $set[] = "`{$k}` = '{$v}'";
        }
      }
 
      $q = "UPDATE `{$options['table']}` SET ".implode(", ", $set)." WHERE `{$this->id}` = '{$id}';";
 
      return $this->_query($q);
 
    } else {
      return false;
    }
  }
  
  // delete
  // builds a DELETE query based on the variables passed
  // all varibles are optional and will default to the current table/id
  // $id can be an associative array of fields/values to match before deleting
  // to delete all news posts by bob you could do:
  //   db->delete(array("user" => "bob"), "news");
  // to delete all news posts by bob with car in the title you could do:
  //   db->delete(array("user" => "bob", "title" => array("mode" => "LIKE", "value" => "%car%")), "news", "OR");
  public function delete($id = null, $options = array()) {
    if (empty($options['table'])) {
      if (!empty($this->table)) {
        $options['table'] = $this->table;
      } else {
        return false;
      }
    }

$where = array();

if (is_array($id)) {
      foreach ($id as $k => $v) {
        if (is_array($v) && isset($v['mode'], $v['value'])) {
          $where[] = "`{$k}` {$v['mode']} '{$v['value']}'";

} elseif ($v === null) {
          $where[] = "ISNULL(`{$k}`)";

} elseif (!is_array($v) && !empty($v)) {
          $where[] = "`{$k}` = '{$v}'";
        }
      }
    } elseif (is_string($id) || is_numeric($id)) {
      $where[] = "`{$this->id}` = {$id}";
    }

if ($mode !== "AND" || $mode !== "OR") {
      $mode = "AND";
    }

$q = "DELETE FROM `{$options['table']}` WHERE ".implode(" {$mode} ", $where);
    
    if (isset($options['limit']) && !empty($options['limit'])) {
      $q .= " LIMIT {$options['limit']}";
    }
    $q .= ";";

return $this->_query($q);
  }
  
  // random
  // returns $n, random rows from $table
  public function random($n = 1, $options = array()) {
    if (empty($options['table'])) {
      if (!empty($this->table)) {
        $options['table'] = $this->table;

} else {
        return false;
      }
    }

if (!is_numeric($n)) {
      $n = 1;
    }

return $this->_get("SELECT * FROM `{$options['table']}` ORDER BY RAND() LIMIT {$n};");
  }
  
  // numRows
  // returns the number of rows in $table
  // $table can be omitted and the number of rows in the current table will be returned
  public function numRows($options = array()) {
    if (empty($options['table'])) {
      if (!empty($this->table)) {
        $options['table'] = $this->table;

} else {
        return false;
      }
    }
    
    $r = $this->_query("SELECT `{$this->id}` FROM `{$options['table']}`;");

return $this->_num_rows($r);
  }
  
  // lastId
  // return the id of the last inserted row
  public function lastId() {
    return $this->_auto_increment_id();
  }
  
  // table
  // creates a clone of the current db object using $options as the default table
  // (or $options['table'] if $options is an array)
  public function table($options = null) {
    if ($options === null && !empty($this->table)) {
      return clone $this;

} elseif (is_string($options) && !empty($options)) {
      $r = clone $this;
      $r->table = $options;

return $r;

} elseif (is_array($options) && isset($options['table']) && !empty($options['table'])) {
      $r = clone $this;
      $r->table = $options['table'];

return $r;

} else {
      return false;
    }
  }
  
  public function getFields($options = array()) {
    if (!empty($this->fields)) {
      return $this->fields;
    } else {
      if (empty($options['table'])) {
        $options['table'] = $this->table;

} else {
        return false;
      }

$q = "SHOW FIELDS FROM `{$options['table']}`;";
      $fields = $this->_get($q, array('raw' => true));

foreach ($fields as $field) {
        if (isset($field['Field'])) {
          $this->fields[] = $field['Field'];
        } elseif (isset($field['field'])) {
          $this->fields[] = $field['Field'];
        } elseif (isset($field[0])) {
          $this->fields[] = $field[0];
        }
      }
    }
    return $this->fields;
  }
  
  public function _new() {
    return new DB_record($this);
  }

}

class DB_record {
  private $_data = array();
  private $_db = null;
  private $_new = false;
  
  function __construct($db = null, $data = null) {
    if (!empty($db)) {
      $this->_db = $db;
    }
    
    if (is_array($data)) {
      $this->_data = $data;

foreach ($this->_data as $key => $value) {
        if (is_array($value)) {
          $this->_data = null;
          break;

} else {
          $this->$key = $value;
        }
      }
    } else {
      $this->_new = true;

if (!empty($this->_db)) {
        foreach ($this->_db->getFields() as $field) {
          if ($field != $this->_db->id) {
            $this->$field = null;
          }
        }
      } else {
        return false;
      }
    }

if (empty($this->_data) || empty($this->_db)) {
      return false;

} else {
      return $this;
    }
  }
  
  function save() {
    $save = array();

foreach ($this->_db->getFields() as $field) {
      if (isset($this->$field) && $field != $this->_db->id) {
        $this->_data[$field] = $this->$field;
        $save[$field] = $this->$field;
      }
    }
    
    $id = $this->_db->id;

if ($this->_new) {
      $r = $this->_db->create($save);
      $this->$id = $this->_db->lastId();
      $this->_new = false;
      return $r;

} else {
      return $this->_db->update($save, $this->$id);
    }
  }
  
  function isNew() {
    return $this->_new;
  }

}
?>

URL: http://www.dom111.co.uk/blog/coding/db/8

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