尝试使用序列对象创建自动编号行的脚本,其中列[姓氏,出生日期,性别]中具有相同值的行被分类为重复项,并且每个重复项分别被分配相同的“外部ID”由序列对象分配........ 当新行通过脚本运行时,如果它无法根据选择列找到匹配项,它应该增加例如R5到R6但如果它可以在表中找到匹配项,它应该分配“先前分配的”[Ext ID]预先存在的匹配,而不是冗余地增加新的[Ext ID]'
Ref Surname Firstname Birthdate Sex ExternalSource Ext ID
1 AAA AA 1/1/2000 M Alpha Null
2 BBB BB 1/1/2001 F Beta Null
3 AAA AA 1/1/2000 M Beta Null
4 CCC CC 1/1/2003 M Alpha Null
5 BBB BB 1/1/2001 F Gamma Null
6 DDD DD 1/1/2004 M Beta Null
7 CCC CC 1/1/2003 M Alpha Null
8 AAA AA 1/1/2000 M Gamma Null
这样脚本相应地填充[Ext ID]列,如下表
Ref Surname Firstname Birthdate Sex ExternalSource Ext ID
1 AAA AA 1/1/2000 M Alpha R1
2 BBB BB 1/1/2001 F Beta R2
3 AAA AA 1/1/2000 M Beta R1
4 CCC CC 1/1/2003 M Alpha R3
5 BBB BB 1/1/2001 F Gamma R2
6 DDD DD 1/1/2004 M Beta R4
7 CCC CC 1/1/2003 M Alpha R3
8 AAA AA 1/1/2000 M Gamma R1
业务场景>该表表示在单独的业务应用程序中具有相同姓氏的行的所有客户记录的联合,生日和&在这些不同的业务应用程序中,性别被认为是相同的“客户”,因此分配相同的[外部ID]值有助于将这些相似的行分类在一起,以便[外部ID]可以在外部用于查询&检索这些值相同的所有记录
进一步澄清 假设'Desired'脚本填充了数据库中加载的'FIRST'基础表的[EXT ID],请有人创建脚本以在另一个表中填充[EXT ID],该表包含新的一组新行,例如基于相同的选择列[姓氏,出生日期,性别],如果在此“新”表和“FIRST”基础表之间找到匹配项,
Ref Surname Firstname Birthdate Sex ExternalSource Ext ID
9 AAA AA 1/1/2000 M Alpha Null
10 EEE EE 1/1/2001 F Beta Null
11 AAA AA 1/1/2000 M Beta Null
12 CCC CC 1/1/2003 M Alpha Null
13 EEE EE 1/1/2001 F Gamma Null
14 FFF FF 1/1/2004 M Beta Null
15 CCC CC 1/1/2003 M Alpha Null
16 AAA AA 1/1/2000 M Gamma Null
从'FIRST'表中的[EXT ID]中检索“NEW”表中指定的[EXT ID],但如果没有匹配,则“NEW”表中指定的[EXT ID]应继续从'FIRST'基础表中最后一个[EXT ID]的末尾开始,例如,如果'FIRST'表中的[EXT ID]是R12,'NEW'表中的[EXT ID]应该是R13
Ref Surname Firstname Birthdate Sex ExternalSource Ext ID
9 AAA AA 1/1/2000 M Alpha R1
10 EEE EE 1/1/2001 F Beta R5
11 AAA AA 1/1/2000 M Beta R1
12 CCC CC 1/1/2003 M Alpha R3
13 EEE EE 1/1/2001 F Gamma R5
14 FFF FF 1/1/2004 M Beta R6
15 CCC CC 1/1/2003 M Alpha R3
16 AAA AA 1/1/2000 M Gamma R1
原因是实际上,新的记录将定期从这些业务应用程序中汇总而来,因为本列永久引用“新”表中的“首页”基础表中的[EXT ID]是理想的作为源业务应用程序的外部参考密钥
答案 0 :(得分:3)
您可以使用DENSE_RANK()
为Surname
,BirthDate
和Sex
的每个唯一组合提供唯一编号,然后将其放入更新语句中进行更新你的专栏:
UPDATE t
SET ExtID = NewExtID
FROM ( SELECT ExtID,
NewExtID = 'R' + CAST(DENSE_RANK()
OVER(ORDER BY Surname, Birthdate, Sex)
AS VARCHAR(10))
FROM dbo.YourTableName
) AS t;
完整的工作示例
IF OBJECT_ID(N'tempdb..#T', 'U') IS NOT NULL
DROP TABLE #T;
CREATE TABLE #T
( Ref INT,
Surname VARCHAR(50),
Firstname VARCHAR(50),
Birthdate DATE,
Sex CHAR(1),
ExternalSource VARCHAR(50),
ExtID VARCHAR(11)
);
INSERT #T (Ref, Surname, Firstname, Birthdate, Sex, ExternalSource)
VALUES
(1, 'AAA', 'AA', '2000-01-01', 'M', 'Alpha'),
(2, 'BBB', 'BB', '2001-01-01', 'F', 'Beta'),
(3, 'AAA', 'AA', '2000-01-01', 'M', 'Beta'),
(4, 'CCC', 'CC', '2003-01-01', 'M', 'Alpha'),
(5, 'BBB', 'BB', '2001-01-01', 'F', 'Gamma'),
(6, 'DDD', 'DD', '2004-01-01', 'M', 'Beta'),
(7, 'CCC', 'CC', '2003-01-01', 'M', 'Alpha'),
(8, 'AAA', 'AA', '2000-01-01', 'M', 'Gamma');
UPDATE t
SET ExtID = NewExtID
FROM ( SELECT ExtID,
NewExtID = 'R' + CAST(DENSE_RANK()
OVER(ORDER BY Surname, Birthdate, Sex)
AS VARCHAR(10))
FROM #T
) AS t;
SELECT *
FROM #T
ORDER BY Ref;
<强>附录强>
为了保持这一点,我建议采用略有不同的方法,并有一个单独的表来维护你的ExtID,这将允许你利用一个标识列:
CREATE TABLE dbo.Ext
(
ID INT IDENTITY(1, 1) NOT NULL,
Surname VARCHAR(50) NOT NULL,
BirthDate DATE NOT NULL,
Sex CHAR(1) NOT NULL,
ExtID AS 'R' + CAST(ExtIntID AS VARCHAR(10)),
CONSTRAINT PK_Ext__ID PRIMARY KEY (ID),
);
CREATE UNIQUE NONCLUSTERED INDEX UQ_Ext__Surname_Birthdate_Sex ON dbo.Ext (Surname, Birthdate, Sex);
实际上,你的基表上有一个类似的索引,你可能不需要这个ExtID列,你可以加入上面的表来获得ExtID并没有太大的性能影响,但是你很可能确实需要更新你可以使用的ExtID列:
MERGE dbo.Ext AS e WITH (HOLDLOCK)
USING
( SELECT DISTINCT Surname, Birthdate, Sex
FROM dbo.YourTable
) AS t
ON t.Surname = e.Surname
AND t.Birthdate = e.Birthdate
AND t.Sex = e.Sex
WHEN NOT MATCHED THEN
INSERT (Surname, Birthdate, Sex)
VALUES (t.Surname, t.Birthdate, t.Sex);
UPDATE t
SET ExtID = r.ExtID
FROM db.YourTable AS t
INNER JOIN dbo.Ext AS e
ON e.Surname = t.Surname
AND e.Birthdate = t.Birthdate
AND e.Sex = t.Sex
WHERE t.ExtID IS NULL;
我使用过MERGE WITH (HOLDLOCK)
,因为这是我所知道的最不容易遇到的竞争条件,并且会遇到唯一的约束违规行为。
如果所有这些都不合适,那么我仍然建议如上所述(如果可能)从标识符中删除R
,并使其只是一个整数。如果需要,您可以将文本列创建为计算列:
CREATE TABLE #T
( Ref INT,
Surname VARCHAR(50),
Firstname VARCHAR(50),
Birthdate DATE,
Sex CHAR(1),
ExternalSource VARCHAR(50),
ExtIntID INT,
ExtID AS 'R' + CAST(ExtIntID AS VARCHAR(10))
);
这样可以使maximim变得更容易,也可能使其他用途更容易。
然后,您的更新语句非常相似:
UPDATE t
SET ExtIntID = NewExtID
FROM ( SELECT t.ExtIntID,
NewExtID = CASE WHEN e.ExtIntID IS NOT NULL THEN e.ExtIntID
ELSE
ISNULL(m.MaxID, 0) +
DENSE_RANK() OVER(PARTITION BY e.ExtIntID
ORDER BY t.Surname, t.Birthdate, t.Sex)
END
FROM #T AS t
LEFT JOIN
( SELECT Surname, Birthdate, Sex, ExtIntID = MAX(ExtIntID)
FROM #T
GROUP BY Surname, Birthdate, Sex
) AS e
ON e.Surname = t.Surname
AND e.Birthdate = t.Birthdate
AND e.Sex = t.Sex
OUTER APPLY (SELECT MAX(ExtIntID) FROM #T) AS m (MaxID)
WHERE t.ExtIntID IS NULL
) AS t;
如果您无法创建INT
列,则更新非常相似,您只需要更多地格式化:
UPDATE t
SET ExtID = NewExtID
FROM ( SELECT t.ExtID,
NewExtID = CASE WHEN e.ExtID IS NOT NULL THEN e.ExtID
ELSE
'R' +
CAST(ISNULL(m.MaxID, 0) +
DENSE_RANK() OVER(PARTITION BY e.ExtID
ORDER BY t.Surname, t.Birthdate, t.Sex)
AS VARCHAR(10))
END
FROM #T AS t
LEFT JOIN
( SELECT Surname, Birthdate, Sex, ExtID = MAX(ExtID)
FROM #T
GROUP BY Surname, Birthdate, Sex
) AS e
ON e.Surname = t.Surname
AND e.Birthdate = t.Birthdate
AND e.Sex = t.Sex
OUTER APPLY (SELECT MAX(CONVERT(INT, SUBSTRING(ExtID, 2, LEN(ExtID)))) FROM #T) AS m (MaxID)
WHERE t.ExtID IS NULL
) AS t;
答案 1 :(得分:1)
使用SELECT DISTINCT仅为每个人获取一次,然后使用ROW_NUMBER()创建您的ID。
SELECT DISTINCT Surname, Birthdate, Sex, ROW_NUMBER() OVER (ORDER by
Surname,Birthdate, Sex) as RowNum
FROM mytable
然后您可以使用它来使用UPDATE语句分配这些值:
UPDATE mytable
SET [Ext ID] = 'R'+cast(RowNum as varchar)
FROM
mytable
INNER JOIN
(SELECT DISTINCT Surname, Birthdate, Sex, ROW_NUMBER() OVER (
ORDER by Surname,Birthdate, Sex) as RowNum
FROM mytable) AS generateIds
ON generateIds.Surname=mytable.Surname
AND generateIds.Birthdate=mytable.Birthdate
NAD generateIds.Sex=mytable.Sex
答案 2 :(得分:0)
您可以查看DENSE_RANK()
https://msdn.microsoft.com/en-us/library/ms173825.aspx
像这样使用:
select 'R' + convert(varchar(100), dense_rank() over (order by Surname, Birthday, Sex)), ...