How to delete the top 1000 rows from a table using Sql Server 2008?

As defined in the link below, you can delete in a straight forward manner

USE AdventureWorks2008R2;
GO
DELETE TOP (20) 
FROM Purchasing.PurchaseOrderDetail
WHERE DueDate < '20020701';
GO

http://technet.microsoft.com/en-us/library/ms175486(v=sql.105).aspx

The code you tried is in fact two statements. A DELETE followed by a SELECT.

You don't define TOP as ordered by what.

For a specific ordering criteria deleting from a CTE or similar table expression is the most efficient way.

;WITH CTE AS
(
SELECT TOP 1000 *
FROM [mytab]
ORDER BY a1
)
DELETE FROM CTE

May be better for sql2005+ to use:

DELETE TOP (1000)
FROM [MyTab]
WHERE YourConditions

For Sql2000:

DELETE FROM [MyTab]
WHERE YourIdField IN 
(
  SELECT TOP 1000 
    YourIdField 
  FROM [MyTab]
  WHERE YourConditions
)

BUT

If you want to delete specific subset of rows instead of arbitrary subset, you should explicitly specify order to subquery:

DELETE FROM [MyTab]
WHERE YourIdField IN 
(
  SELECT TOP 1000 
    YourIdField 
  FROM [MyTab]
  WHERE YourConditions
  ORDER BY ExplicitSortOrder
)

Thanks tp @gbn for mentioning and demanding the more clear and exact answer.

Related