在沒有連接或聯合的情況下在mysql中連接兩個結果集

Question

我在下面有兩組結果集。

SELECT * FROM `mfw_host` 
WHERE host_id IN 
(SELECT host_id FROM `latest_tech` 
WHERE `nav_node_id` = 213) 



SELECT * FROM `mfw_navnode` 
WHERE host_id IN 
(SELECT host_id FROM mfw_host 
WHERE host_id IN (SELECT host_id FROM `latest_tech` 
WHERE `nav_node_id` = 213)) 

我是加入兩個結果together..without加入和工會什麼（因爲他們有連接them..and領域按鍵沒有對每一組不同的結果）。

我該如何實現？

UPDATE：.... ANSWER修訂見上文..

我想從兩組添加上述結果together..they返回5行，每行，並且具有不同的列號檢索的每個

試了一個解決辦法：

SELECT 
    a.* 
    , b.* 
FROM 
    (SELECT * FROM `mfw_host` 
WHERE host_id IN 
(SELECT host_id FROM `latest_tech` 
WHERE `nav_node_id` = 213) 
) AS a 
    CROSS JOIN 
    (SELECT * FROM `mfw_navnode` 
WHERE host_id IN 
(SELECT host_id FROM mfw_host 
WHERE host_id IN (SELECT host_id FROM `latest_tech` 
WHERE `nav_node_id` = 213)) 
) AS b 

這種交叉連接返回太多行

Answer 1

您可以爲其他查詢中不存在的字段獲取一些默認值。假設在mfw_host中有字段：id，hostname，ip;在mfw_navnode中你有id，name，create_date。然後您的查詢可能是

SELECT 0 AS type, id, host_name, ip, '' AS node_name, 
    NULL AS create_date FROM mfw_host 
WHERE host_id IN (
    SELECT host_id FROM `latest_tech` WHERE `nav_node_id` = 213) 
UNION 
SELECT 1 AS type, id, '' AS host_name, NULL AS ip, node_name, create_date 
    FROM `mfw_navnode` WHERE `parent_id`=213 

類型是讓你知道哪個表是哪一行。但沒有必要。