Drupal - Custom functions

I created the functions below to easily process the values of a $field in a $table by $number using the specified $params.

Explanation: $number = number
$field = string
$table = string(schema name)
$params = array(
  'fields' => array('uid','nid',...),
  'select' => array('=','>','<',...),
  'update' => array('=','>','<',...),
  'values' => array('1','1',...),
);

/*
 * This function increases by $number,
 * the $field of the $table WHERE $params
 * are valid. This function assumes the
 * field needs to be updated and NOT created.
 */
function module_increase_field($table,$field,$number,$params){
  $select = "SELECT {$field} FROM {".$table."}";
  if(!empty($params['fields'])){
    $select .= " WHERE ";
    for($i=0;$i<count($params['fields']);$i++){
      $select .= $params['fields'][$i].$params['select'][$i]."'".$params['values'][$i]."',";
    }
    $select = substr($select,0,strlen($select)-1);
    $value = db_result(db_query($select),0);
    $value++;
    $update = "UPDATE {".$table."} SET {$field}='{$value}' WHERE ";
    for($i=0;$i<count($params['fields']);$i++){
      $update .= $params['fields'][$i].$params['update'][$i]."'".$params['values'][$i]."' AND ";
    }
    $update = substr($update,0,strlen($update)-4);
    db_query($update);
  }else{
    watchdog('Modify field',t('The $params array is empty'));
  }
}

/*
 * This function increases by $number,
 * the $field of the $table WHERE $params
 * are valid. This function assumes the
 * field needs to be updated and NOT created.
 *
 * @see function module_increase_field()
 * for more information
 */
function module_decrease_field($table,$field,$number,$params){
  $select = "SELECT {$field} FROM {".$table."}";
  if(!empty($params['fields'])){
    $select .= " WHERE ";
    for($i=0;$i<count($params['fields']);$i++){
      $select .= $params['fields'][$i].$params['select']."'".$params['values'][$i]."',";
    }
    $select = substr($select,0,strlen($select)-1);
    $value = db_result(db_query($select),0);
    $value++;
    $update = "UPDATE {".$table."} SET {$field}='{$value}' WHERE";
    for($i=0;$i<count($params['fields']);$i++){
      $update .= $params['fields'][$i].$params['update'][$i]."'".$params['values'][$i]."' AND ";
    }
    $update = substr($update,0,strlen($update)-4);
    db_query($update);
  }else{
    watchdog('Modify field',t('The $params array is empty'));
  }
}

/*
 * This function returns the number of
 * $field(s) the $table has WHERE $params
 * are valid.
 *
 * @see function_module_increase_field()
 * for more information
 */
function module_count_field($table,$field,$params){
  $sql = "SELECT COUNT({$field}) FROM {".$table."}";
  if(!empty($params['fields'])){
    $sql .= " WHERE ";
    for($i=0;$i<count($params['fields']);$i++){
      $sql .= $params['fields'][$i].$params['select'][$i]."'".$params['values'][$i]."' AND ";
    }
    $sql = substr($sql,0,strlen($sql)-4);
  }
  return db_result(db_query($sql));
}