/**
* 格式化为字符串
*
* @param QDB_Adapter_Abstract $conn
* @param string $table_name
* @param array $mapping
* @param callback $callback
*
* @return string
*/
function formatToString($conn, $table_name = null, array $mapping = null, $callback = null)
{
if (!is_array($mapping)) {
$mapping = array();
}
return $conn->qsql($this->_expr, $table_name, $mapping, $callback);
}
/**
* 添加一个集合查询
*
* @param int $type
* @param string|QDB_Expr $field
* @param string $alias
*
* @return QDB_Select
*/
protected function _addAggregate($type, $field, $alias)
{
$this->_parts[self::COLUMNS] = array();
$this->_query_params[self::RECURSION] = 0;
if ($field instanceof QDB_Expr) {
$field = $field->formatToString($this->_conn, $this->_getCurrentTableName(), $this->_columns_mapping);
} else {
if (isset($this->_columns_mapping[$field])) {
$field = $this->_columns_mapping[$field];
}
$field = $this->_conn->qsql($field, $this->_getCurrentTableName(), $this->_columns_mapping);
$field = "{$type}({$field})";
}
$this->_parts[self::AGGREGATE][] = array($type, $field, $alias);
$this->_query_params[self::AS_ARRAY] = true;
return $this;
}