的Oracle SQL結果

Question

我已經寫在甲骨文的SQL查詢返回的結果如下：

accountName1 null 
null   hostName 
accountName2 null 
null   hostName 

相反，我想結果看起來像：

accountName1 hostName 
accountName2 hostName 

Answer 1

假設一個或其它列值始終爲NULL then：

SELECT MAX(account_name) AS account_name, 
     MAX(host_name ) AS host_name 
FROM (
    SELECT t.*, 
     NVL2(
      account_name, 
      ROW_NUMBER() OVER (ORDER BY NVL2(account_name, ROWNUM, NULL) NULLS LAST), 
      ROW_NUMBER() OVER (ORDER BY NVL2(host_name, ROWNUM, NULL) NULLS LAST) 
     ) AS rn 
    FROM your_table t 
) 
GROUP BY rn;