how can I Update top 100 records in sql server

Question

I want to update the top 100 records in SQL Server. I have a table T1 with fields F1 and F2. T1 has 200 records. I want

Answer 1

Try:

UPDATE Dispatch_Post
SET isSync = 1
WHERE ChallanNo 
IN (SELECT TOP 1000 ChallanNo FROM dbo.Dispatch_Post ORDER BY 
CreatedDate DESC)

Answer 2

Without an ORDER BY the whole idea of TOP doesn't make much sense. You need to have a consistent definition of which direction is "up" and which is "down" for the concept of top to be meaningful.

Nonetheless SQL Server allows it but doesn't guarantee a deterministic result.

The UPDATE TOP syntax in the accepted answer does not support an ORDER BY clause but it is possible to get deterministic semantics here by using a CTE or derived table to define the desired sort order as below.

;WITH CTE AS 
( 
SELECT TOP 100 * 
FROM T1 
ORDER BY F2 
) 
UPDATE CTE SET F1='foo'

Answer 3

What's even cooler is the fact that you can use an inline Table-Valued Function to select which (and how many via TOP) row(s) to update. That is:

UPDATE MyTable
SET Column1=@Value1
FROM tvfSelectLatestRowOfMyTableMatchingCriteria(@Param1,@Param2,@Param3)

For the table valued function you have something interesting to select the row to update like:

CREATE FUNCTION tvfSelectLatestRowOfMyTableMatchingCriteria
(
    @Param1 INT,
    @Param2 INT,
    @Param3 INT
)
RETURNS TABLE AS RETURN
(
    SELECT TOP(1) MyTable.*
    FROM MyTable
    JOIN MyOtherTable
      ON ...
    JOIN WhoKnowsWhatElse
      ON ...
    WHERE MyTable.SomeColumn=@Param1 AND ...
    ORDER BY MyTable.SomeDate DESC
)

..., and there lies (in my humble opinion) the true power of updating only top selected rows deterministically while at the same time simplifying the syntax of the UPDATE statement.

Answer 4

You can also update from select using alias and join:

UPDATE  TOP (500) T
SET     T.SomeColumn = 'Value'
FROM    SomeTable T
        INNER JOIN OtherTable O ON O.OtherTableFK = T.SomeTablePK
WHERE   T.SomeOtherColumn = 1

Answer 5

update tb set  f1=1 where id in (select top 100 id from tb where f1=0)

Answer 6

Note, the parentheses are required for UPDATE statements:

update top (100) table1 set field1 = 1