在 SQL 插入时递增序列号

Question

有没有使用 SQL Server 2005 插入多行并增加特定字段的简单方法？

注意，我不是在寻找涉及 identity 列的解决方案 - 请参阅问题底部以获取解释

（以下架构和数据已复制here in this SQLFiddle。）

例如，考虑下表和数据...

CREATE TABLE #TEMPTABLE (
   [PKID] INT IDENTITY, [FKID] INT, [MYTEXT] VARCHAR(10), [SEQUENCE] INT
)
INSERT INTO #TEMPTABLE ([FKID], [MYTEXT], [SEQUENCE]) VALUES (1, 'one', 1)
INSERT INTO #TEMPTABLE ([FKID], [MYTEXT], [SEQUENCE]) VALUES (1, 'two', 2)

-- Table data
PKID  FKID  MYTEXT  SEQUENCE
1     1     one     1
2     1     two     2

还有下面要插入的数据……

DECLARE @FKID INT
SET @FKID = 1
DECLARE @NEWDATA XML
SET @NEWDATA = '<data><text>three</text><text>four</text></data>'

以下内容可以写成SEQUENCE 字段显示为1,2,3,4 而不是当前的1,2,3,3？

INSERT INTO #TEMPTABLE ([FKID], [MYTEXT], [SEQUENCE])
SELECT @FKID, 
       X.value('.','VARCHAR(10)'),
       (SELECT ISNULL(MAX([SEQUENCE]),0)+1 FROM #TEMPTABLE WHERE [FKID]=@FKID)
FROM @NEWDATA.nodes('/data/text') AS X(X)

-- Actual result...
PKID  FKID  MYTEXT  SEQUENCE
1     1     one     1
2     1     two     2
3     1     three   3
4     1     four    3  <-- Issue

-- Required result...
PKID  FKID  MYTEXT  SEQUENCE
1     1     one     1
2     1     two     2
3     1     three   3
4     1     four    4

---

更新：

回应@marc_s 的评论...

Identity 将是 2005 年的最佳解决方案......迄今为止最好的解决方案 - 为什么您明确排除它并坚持推出自己的解决方案？ （有导致重复等的所有风险......）

有问题的表将保存多组 SEQUENCE 值，每个“组”都基于 FKID 值...因此该表可以保存这些数据...

PKID  FKID  MYTEXT  SEQUENCE
1     1     one     1
2     1     two     2
3     1     three   3
4     1     four    4
5     2     ett     1
6     2     tva     2
7     2     tre     3

Answer 1

我无法在 2005 年进行测试，但您应该可以使用 CTE 对事物进行编号；

DECLARE @FKID INT
SET @FKID = 1
DECLARE @NEWDATA XML
SET @NEWDATA = '<data><text>three</text><text>four</text><text>five</text></data>'

;WITH cte AS (SELECT @FKID FKID, X.value('.','VARCHAR(10)') a, 
                  ROW_NUMBER() OVER (ORDER BY X) r
             FROM @NEWDATA.nodes('/data/text') AS X(X))
INSERT INTO TEMPTABLE ([FKID], [MYTEXT], [SEQUENCE])
SELECT fkid, a,
  (SELECT ISNULL(MAX([SEQUENCE]),0)+r FROM TEMPTABLE WHERE [FKID]=cte.fkid)
FROM cte;

SELECT * FROM TEMPTABLE;

给出结果：

1    1    one     1
2    1    two     2
3    1    three   3
4    1    four    4
5    1    five    5

---

更新

如果查询将只插入一个 FKID，则以下简化版本也可以工作（突出显示对当前查询的必要更改）：

INSERT INTO #TEMPTABLE ([FKID], [MYTEXT], [SEQUENCE])
SELECT @FKID, 
       X.value('.','VARCHAR(10)'),
       (SELECT ISNULL(MAX([SEQUENCE]),0)+1 FROM #TEMPTABLE WHERE [FKID]=@FKID)
        + ROW_NUMBER() OVER (ORDER BY (SELECT 1))
FROM @NEWDATA.nodes('/data/text') AS X(X)

ROW_NUMBER 的ORDER BY 子句中(SELECT 1) 的目的是避免指定任何特定的顺序。如有必要，可以将其更改为其他内容（例如，X.value('.','VARCHAR(10)'）。

Answer 2

怎么样

    INSERT INTO #TEMPTABLE ([FKID], [MYTEXT], [SEQUENCE])
    SELECT @FKID, 
               X.value('.','VARCHAR(10)'),
              (SELECT ISNULL(Count(*),0)+1 FROM #TEMPTABLE)
    FROM @NEWDATA.nodes('/data/text') AS X(X)

Answer 3

试试这个：

with data as (
  select * from ( values
    (1,1,'one'),
    (2,1,'two'),
    (3,1,'three'),
    (5,1,'five'),
    (6,1,'six')
  ) data(PKID, FKID, MYTEXT)
) 
select lhs.*, sequence = count(*)
from data lhs
left join data rhs on rhs.FKID = lhs.FKID 
  and rhs.PKID <= lhs.PKID
group by 
  lhs.PKID,
  lhs.FKID,
  lhs.MYTEXT

产生这个：

PKID        FKID        MYTEXT sequence
----------- ----------- ------ -----------
1           1           one    1
2           1           two    2
3           1           three  3
5           1           five   4
6           1           six    5