/**
  * replaces wildcards of a single value
  *
  * @param  string $value
  * @return string
  */
 protected function _replaceWildcardsSingleValue($value)
 {
     $action = $this->_opSqlMap[$this->_operator];
     // replace wildcards from user ()
     $returnValue = str_replace(array('*', '_'), $this->_dbCommand->setDatabaseJokerCharacters(), $value);
     // add wildcard to value according to operator
     $returnValue = str_replace('?', $returnValue, $action['wildcards']);
     return $returnValue;
 }