将列插入到视图中，该视图将为每个唯一的主键分配唯一的ID

Question

我正在尝试在SQL Server 2012的视图中插入一个新列，为每个唯一TxnID分配一个新号码。

目前，TxnID长度为28个字符。如果我可以为每个TxnID分配一个以“1”开头的新号码，那就太棒了。

Current TxnID 
-------------------------
2010100009000010000006783
2010100009000010000006784
2010100009000010000006785
2010100009000010000006785

所需的TxnID

1
2
3
3

Answer 1

使用可能有帮助的排名函数rank()

select *, rank() over (order by TxnID) TxnID from table 

Answer 2

使用ROW_NUMBER（）

CREATE VIEW DBO.Vw_MyView
AS
SELECT
    TxnID = ROW_NUMBER() OVER(ORDER BY TxnID),
    *
    FROM YourTable

Answer 3

我们可以使用很多方法 -

- RANK（）

SELECT * , RANK() OVER (ORDER BY [Current TxnID]) rowNumx FROM (
SELECT '2010100009000010000006783' [Current TxnID] UNION ALL
SELECT '2010100009000010000006784' UNION ALL
SELECT '2010100009000010000006785' UNION ALL
SELECT '2010100009000010000006785' )p

- DENSE_RANK

SELECT * , DENSE_RANK() OVER (ORDER BY [Current TxnID]) rowNumx FROM (
SELECT '2010100009000010000006783' [Current TxnID] UNION ALL
SELECT '2010100009000010000006784' UNION ALL
SELECT '2010100009000010000006785' UNION ALL
SELECT '2010100009000010000006785' )p

- 其他

;WITH CTE AS
(
    SELECT '2010100009000010000006783' [Current TxnID] UNION ALL
    SELECT '2010100009000010000006784' UNION ALL
    SELECT '2010100009000010000006785' UNION ALL
    SELECT '2010100009000010000006785' 
)
SELECT [Current TxnID], rowNumx = ( SELECT COUNT(*)+1 FROM CTE c1 WHERE c1.[Current TxnID] < c.[Current TxnID] )
FROM CTE c

OUTPUT For all

/*------------------------
OUTPUT
------------------------*/
Current TxnID             rowNumx
------------------------- --------------------
2010100009000010000006783 1
2010100009000010000006784 2
2010100009000010000006785 3
2010100009000010000006785 3

(4 row(s) affected)