連接表（無條款）

Question

我想加入到表，並得到下面的輸出

表1

TestId1 
---------- 
one 
two 
three 
four 
five 
six 
seven 
eight 

表2

TestId2 
---------- 
fiftythree 
fiftyfour 
fiftytwo 
fiftyfive 
fiftyone 

我想表3爲我的輸出來自table1的所有行和來自table2的第一行，直到沒有剩下的行，然後它們應該開始重複。

作爲替代答案，它們也可以隨機分配。

TestId1  TestId2 
----------  ---------- 
one   fiftythree 
two   fiftyfour 
three   fiftytwo 
four   fiftyfive 
five   fiftyone 
six   fiftythree 
seven   fiftyfour 
eight   fiftytwo 

Answer 1

試試這個：

SELECT t1.name, t2.name FROM 
(
    SELECT (ROW_NUMBER() OVER(ORDER BY name)-1)%(SELECT COUNT(*) FROM test2) AS j,* 
    FROM test1 
) t1 
INNER JOIN 
(
    SELECT ROW_NUMBER() OVER(ORDER BY name)-1 AS j,* 
    FROM test2 
) t2 ON t1.j = t2.j 
ORDER BY t1.name 

在細節：

SELECT (ROW_NUMBER() OVER(ORDER BY name)-1) AS j,* 
FROM test1 

返回：

0 | one 
1 | two 
2 | three 
3 | four 
4 | five 
5 | six 
6 | seven 
7 | eight 

此：

SELECT ROW_NUMBER() OVER(ORDER BY name)-1 AS j,* 
FROM test2 

返回：

0 | fiftythree 
1 | fiftyfour 
2 | fiftytwo 
3 | fiftyfive 
4 | fiftyone 

所有你需要做的是分裂 - 由元素的數量（％我不知道這個英文名）的最長表的第一列短：

SELECT (ROW_NUMBER() OVER(ORDER BY name)-1)%(SELECT COUNT(*) FROM test2) AS j,* 
FROM test1 

返回：

0 | one 
1 | two 
2 | three 
3 | four 
4 | five 
0 | six 
1 | seven 
2 | eight 

所有你現在要做的是加入微博第一列的第一個表格。

該解決方案是通過僅使用一個查詢來完成的，但它假設在table1中有更多的元素，然後在table2中。如果你不喜歡這個解決方案，我只是給你編寫存儲過程的良好基礎。

Answer 2

您可能想嘗試在ROWNUM上進行JOINING。

http://www.adp-gmbh.ch/ora/sql/rownum.html

Answer 3

您的替代解決方案是唯一一個

SELECT 
    TestID1, 
    TestID2 
FROM 
    (SELECT COUNT(*) AS Count1 FROM Table1) C1 --one row 
    CROSS JOIN 
    (SELECT COUNT(*) AS Count2 FROM Table2) C2 --one row 
    CROSS JOIN 
    (
    SELECT 
     ROW_NUMBER() OVER (ORDER BY TestID1) AS Rank1, 
     TestID1, 
    FROM 
     Table1 
    ) t1 
    JOIN 
    (
    SELECT 
     ROW_NUMBER() OVER (ORDER BY TestID1) AS Rank2, 
     TestID2, 
    FROM 
     Table2 
    ) t2 ON 
     t1.Rank1 % CASE WHEN C1.Count1 > C2.Count2 THEN C2.Count2 ELSE 2000000000 END 
     = 
     t2.Rank2 % CASE WHEN C2.Count2 > C1.Count1 THEN C1.Count1 ELSE 2000000000 END 
ORDER BY 
    t1.Rank1, t2.Rank2 

Answer 4

我想通過一個選擇所有的解決方案是十分可怕的。我想更好地利用存儲過程與兩個光標（在每個表）

Answer 5

這這裏工作並且只有一個光標：

if exists(select object_id('tempdb..#TestId1')) 
drop table #TestId1 

if exists(select object_id('tempdb..#TestId2')) 
drop table #TestId2 

if exists(select object_id('tempdb..#result')) 
drop table #result 

create table #TestId1(col_1 varchar(100)) 

create table #TestId2(col_2 varchar(100)) 

create table #result (col_1 varchar(100), col_2 varchar(100)) 

set rowcount 0 

insert into #TestId1(col_1) 
select col='one' 
union all select col='two' 
union all select col='three' 
union all select col='four' 
union all select col='five' 
union all select col='six' 
union all select col='seven' 
union all select col='eigh' 

insert into #TestId2(col_2) 
select col='fiftythree' 
union all select col='fiftyfour' 
union all select col='fiftytwo' 
union all select col='fiftyfive' 
union all select col='fiftyone' 

DECLARE @sectblcnt int 
select @sectblcnt=count(*) from #TestId2 

DECLARE @sectableNo int 

DECLARE @rowno int 

declare @col_1 varchar(100), @col_2 varchar(100) 

set @rowno=0 

DECLARE curs CURSOR FOR SELECT col_1 FROM #TestId1 

OPEN curs 

FETCH NEXT FROM curs INTO @col_1 

WHILE @@FETCH_STATUS = 0 
BEGIN 
set @rowno=@rowno+1; 

set @sectableNo = @rowno % @sectblcnt 
set rowcount @sectableNo 

select @col_2=col_2 from #TestId2 

insert into #result(col_1, col_2) 
    values(@col_1, @col_2) 

FETCH NEXT FROM curs 
INTO @col_1 
END 

CLOSE curs 

DEALLOCATE curs 

set rowcount 0 

select * from #result 

Answer 6

我喜歡隨機過程，所以拍得[僞]隨機解決方案 ;-)

這也需要在表2上「誘導」一個行號，但與Table1的連接是由表1的一些列上的一些哈希[以模塊化表2的行數爲模]驅動的不必是TestId1）。

SELECT T1.TestId1, T2.TestId2 
FROM Table1 T1 
JOIN (
    SELECT (ROW_NUMBER() OVER(ORDER BY TestId2) - 1) AS RowNum, TestId2 
    FROM Table2 
) T2 ON ABS(HashBytes ('MD5', T1.TestId1) % (SELECT COUNT(*) FROM Table2)) 
     = T2.RowNum 
ORDER BY t1.TestId1