src/DB/Drivers/PDOSqlDriver.php
public function fetchOne(
        $sql,
        $fetch_style = PDO::FETCH_ASSOC,
        $cursor_orientation = PDO::FETCH_ORI_NEXT,
        $cursor_offset = 0
    )
    {
        try {
            return $this->pdo->query($sql)->fetch($fetch_style, $cursor_orientation, $cursor_offset);
        } catch (Exception $e) {
            throw new CoreException($e->getMessage());
        }
    }
public function fetchOne(
        $sql,
        $fetch_style = PDO::FETCH_ASSOC,
        $cursor_orientation = PDO::FETCH_ORI_NEXT,
        $cursor_offset = 0
    )
    {
        try {
            return $this->pdo->query($sql)->fetch($fetch_style, $cursor_orientation, $cursor_offset);
        } catch (Exception $e) {
            throw new CoreException($e->getMessage());
        }
    }
执行一条SQL 语句 并返回结果

@param string $sql
@param int $fetch_style
@param int $cursor_orientation
@param int $cursor_offset
@return mixed
@throws CoreException