循環和聯合所有在oracle select語句中

Question

我在oracle中有下表。版本9i

Num   count 

123    1 
345    4 
455    3 
234    2 
542    1 

我想寫一個選擇查詢，它給了我下面的輸出。

123 
345 
345 
345 
345 
455 
455 
455 
234 
234 
542 

每個數字應顯示其計數次數。如果我使用功能，這可以實現嗎？我不允許創建任何臨時表。

我知道我必須使用循環序列，然後使用UNION ALL，但不知道如何實現它。我想這

select Num from <table> where count=1 
union all 
// what fits here? 

Answer 1

這可以通過使用僞列LEVEL和Correlated Query爲重複的次數NUM計數來完成...

嘗試下面的查詢

select num from (select distinct num,level,ROWID as RD 
from table a 
connect by level<= (select count from table b where a.num=b.num)) 
order by rd; 

Answer 2

試試這個

SELECT A.NUM 
FROM Test A 
INNER JOIN (SELECT ROWNUM RN FROM dual connect by level < 100) B 
ON B.rn <= A.count 
order by A.NUM; 

SQL DEMO

Answer 3

WITH cte ("Num", "count") 
AS 
(
    SELECT "Num", "count" FROM TableName 
    UNION ALL 
    SELECT "Num", "count" - 1 FROM cte WHERE "count" > 1 
) 
SELECT "Num" 
FROM cte 
ORDER BY "Num" 

• SQLFiddle Demo

Answer 4

如果您使用11gR2中，你可以做它是這樣的：

with t(num, i) as 
(
    select num, count from tab1 union all 
    select num, i-1 
    from t 
    where i >1 
)  
select num from t 
order by num; 

Here is a sqlfiddle demo