Question

我有一个表，我想在其中更新特定列的值。列值应为行号。基于列的不同值，我需要更新新创建的列值。

示例：

INFO_T表的内容：

Name   | id 
------------
Arijit | 120
Suman  | 240
Priyam | 555
Arijit | 456
Suvayu | 110
Priyam | 300

我需要在上表INFO_T中添加一个列，下面是示例。我必须使用ROW_NUMBER() OVER函数，我必须通过该函数更新SEQ_NO列。

Name   | id  | Seq_no
------------------
Arijit | 120 | 1
Suman  | 240 | 2
Priyam | 555 | 3
Arijit | 120 | 1
Suvayu | 110 | 4
Priyam | 555 | 3

如何获得上述结果？

Answer 1

SQL FIDDLE DEMO

SELECT Table1.name, Table1.ID, SEQ.Seq_no
FROM 
    (SELECT name, ROW_NUMBER() OVER(order by name) as Seq_no
     FROM (SELECT  DISTINCT name FROM Table1) as unique_name ) as SEQ INNER JOIN
     Table1 on SEQ.name = Table1.Name

Answer 2

您可以将Private Sub Command0_Click() Dim rst As DAO.Recordset Set rst = CurrentDb.OpenRecordset("SELECT DISTINCT [Portfolio Code], [Trustee 1] FROM [General] ORDER BY [Portfolio Code];", dbOpenSnapshot) Do While Not rst.EOF strRptFilter = "[Portfolio Code] = " & Chr(34) & rst![Portfolio Code] & Chr(34) DoCmd.OutputTo acOutputReport, "Main Report", acFormatPDF, "O:\Annual Review\AnnualReviewReport" & "\" & rst![Trustee 1] & "\" & rst![Portfolio Code] & " - " & rst![Trustee 1] & ".pdf" DoEvents rst.MoveNext Loop rst.Close Set rst = Nothing End Sub用于此目的：

dense_rank()

如果您只想使用select name, id, dense_rank() over (order by minid) as seqno from (select t.*, min(id) over (partition by name) as minid from table t ) t;执行此操作：

row_number()

但是，我不知道你为什么要那样做。

Answer 3

这是MS SQL，但看起来Row_Number在Oracle中的功能相同。如果您不能执行CTE（WITH）语句，则可以将这些语句作为子查询来完成。也许具有Oracle SQL经验的人可以使用此示例并重新编写它。我不能保证结果，因为它们是无序的，但基本上我首先从表中创建一个没有顺序的RowID。这使我能够确保名称与您拥有的名称相同（这似乎是插入顺序）。然后我基本上做了子查询，以便按顺序获取每个名称的FIRST不同实例。然后我加入了原来的桌子。这是SQLFiddle。

;WITH NoOrderBy AS
(
  select Row_Number() OVER(ORDER BY (SELECT 0)) RowID,Name,id
  FROM MyTable
),
DistinctNames  AS
(
  SELECT Row_Number() OVER(ORDER BY RowID) RowID3,Name,RowID,id
  FROM
  (
    SELECT Row_Number() OVER(PARTITION BY NAME ORDER BY RowID) RowID2,Name,RowID,id
    FROM NoOrderBy
   ) a
   WHERE RowID2 = 1
)
SELECT mt.Name,di.id,di.RowID3 Seq_no 
FROM MyTable mt
INNER JOIN DistinctNames di
ON mt.Name =di.Name

如何使用ROW_NUMBER（）OVER值更新列值，该值基于列的不同值

3 个答案: