跳過一些使用連接生成的數字序列由

Question

Select Rownum From dual Connect By Rownum <= '4' ; 

使用該SQL列出數字1到4

我想列出1至4跳繩3，這樣的結果看起來像

AM

1 
2 
4 

請幫助

Answer 1

SELECT CASE WHEN LEVEL < 3 THEN LEVEL ELSE LEVEL + 1 END AS value 
FROM DUAL 
CONNECT BY LEVEL < 4; 

或

SELECT * 
FROM (
    SELECT LEVEL AS value 
    FROM DUAL 
    CONNECT BY LEVEL <= 4 
) 
WHERE value <> 3; 

，或者因爲它是不清楚你的順序應該如何超越4進展情況，你可以這樣做：

SELECT POWER(2, LEVEL - 1) AS value 
FROM DUAL 
CONNECT BY LEVEL <= 3;