问题
For the selected rows in a column, how to update each row sequentially from the beginning to the end, with each row value incremented by 1 (or certain number). I know this can be done in excel in few seconds but I could figure out how to achieve in SQL server. For instance:
customer id is NULL now update customer id with every row incremented by 1 (i.e. first row = 1, second row = 2, .....nth row = n)
ship-to party customer id
0002018092 NULL
0002008127 NULL
0002000129 NULL
0002031592 NULL
0002034232 NULL
desired output
ship-to party customer id
0002018092 1
0002008127 2
0002000129 3
0002031592 4
0002034232 5
Also, for the selected rows in a column, how to update each row with the row number? I know there is a row_number() function but didn't succeed in producing the desired result. for instance
column A is NULL now update Column A with every row incremented by 1 (i.e. first row = row number 1, second row = row number 2, .....nth row = row number n)
Any demonstration would be very helpful.thkans
回答1:
example : suppose I want to add a value to each value in column SomeIntField
in table tblUser
there are 2 ways of doing this easy
first: this just adds value 1 to each column SomeIntField
update tblUser set SomeIntField = SomeIntField + 1
second : this adds an incrementing value, the first row gets +1, second gets +2, and so on...
declare @number int = 0
update tblUser
set @number = @number + 1,
SomeIntField = isnull(SomeIntField, 0) + @Number
EDIT: based on your last comment this might be what you want
declare @table table (shiptoparty varchar(50), customer_id int)
insert into @Table (shiptoparty, customer_id)
values ('0002018092', NULL), ('0002008127', NULL), ('0002000129', NULL), ('0002031592', NULL), ('0002034232', NULL)
declare @number int = 0
update @table
set @number = @number + 1,
customer_id = isnull(customer_id, 0) + @Number
select * from @table
The result of this is :
shiptoparty | customer_id
----------- | -----------
0002018092 | 1
0002008127 | 2
0002000129 | 3
0002031592 | 4
0002034232 | 5
回答2:
To update each row with row number
Try below
CREATE TABLE tmp(Id INT IDENTITY(1,1), Value INT)
INSERT INTO tmp(value) VALUES(1),(2),(3),(4),(5)
UPDATE T
SET
T.Value = B.RowNo
FROM tmp AS T
INNER JOIN (SELECT Id, ROW_NUMBER()OVER(ORDER BY Id) AS RowNo FROM tmp)AS B
ON T.Id = B.Id
回答3:
Rather than using a self referencing variable, use a CTE:
WITH CTE AS (
SELECT [Your Incrementing Column],
ROW_NUMBER() OVER (ORDER BY [Columns to Order By]) AS RN
FROM YourTable)
UPDATE CTE
SET [Your Incrementing Column] = RN;
Edit: To prove a point that ALL rows will be updated:
CREATE TABLE #Sample (String varchar(50),
IncrementingInt int);
INSERT INTO #Sample (String)
VALUES ('sdkfjasdf'),
('dfydsfdfg'),
('sdfgsdfg45yfg'),
('dfgf54d'),
('dsft43tdc'),
('f6gytrntrfu7m45'),
('5d6f45wgby54'),
('g34h636j'),
('jw'),
('h6nw54m'),
('g54j747jm5e5f4w5gsft'),
('ns67mw54mk8o7hr'),
('h45j4w5h4');
SELECT *
FROM #Sample;
WITH CTE AS(
SELECT IncrementingInt,
ROW_NUMBER() OVER (ORDER BY String) AS RN
FROM #Sample)
UPDATE CTE
SET IncrementingInt = RN;
SELECT *
FROM #Sample;
DROP TABLE #Sample;
GO
回答4:
First problem:
you want to increase values in every row in certain column by 1 (or other nuber), try this:
update TABLE_NAME set column_to_increase = column_to_increase + 1
Second problem:
you want to get row number for only certain rows. Solution: first create column holding all row numbers, then get the rows:
select * from (
select column1, column2, ..., columnN, row_number() over (order by (select null)) as [rn] from MY_TABLE
) where *condition*
FYI: select null
in over
clause does exactly nothing, it's just there, because window functions (such as row_number
) have to have over
clause and some of them require order by
.
来源:https://stackoverflow.com/questions/47711625/sql-how-to-update-a-column-with-each-row-value-incremented-by-1