有没有更好的方法来在SQL服务器中进行分页?
例如,我必须使用以下技术将@skip添加到@take:
;WITH tmp_cte AS (
SELECT ROW_NUMBER() OVER (ORDER BY LastName) AS RowNumber,
LastName,
FirstName
FROM person.Person
WHERE FirstName like '%ad%'
)
SELECT *
FROM tmp_cte
WHERE RowNumber > @skip --10
AND RowNumber <= @Take--20
有没有更好的方法让我不必添加跳过?
在SQL 2012中非常简单:
SELECT LastName, FirstName
FROM person.Person
WHERE FirstName like '%ad%'
ORDER BY LastName
OFFSET 10 ROWS
FETCH NEXT 10 ROWS ONLY;
查看此链接,了解其他版本的 SQL 服务器 + 性能比较。
如果 Person.Person 表上有一个唯一索引(例如,PersonID
列上有一个唯一索引,并且此索引是聚集的 - 例如,如果你有一个聚集的 PK),则可以提供更好的解决方案。在这种情况下,上述查询可以重写为:
;WITH tmp_cte AS (
SELECT ROW_NUMBER() OVER (ORDER BY LastName) AS RowNumber, PersonID
FROM person.Person
WHERE FirstName like '%ad%'
)
SELECT ...
FROM Person.Person p
WHERE p.PersonID IN -- PersonID is the key of this UNIQUE INDEX
(
SELECT PersonID FROM tmp_cte
WHERE RowNumber > @skip 10 AND RowNumber <= @Take--20
)
或
DECLARE @Rows TABLE (ID INT PRIMARY KEY);
;WITH tmp_cte AS (
SELECT ROW_NUMBER() OVER (ORDER BY LastName) AS RowNumber, PersonID
FROM person.Person
WHERE FirstName like '%ad%'
)
INSERT @Rows (ID)
SELECT PersonID FROM tmp_cte
WHERE RowNumber > @skip 10 AND RowNumber <= @Take--20
SELECT ...
FROM Person.Person p
WHERE p.PersonID IN (SELECT ID FROM @Rows); -- PersonID is the key of this UNIQUE INDEX
注意#1:在这种特殊情况下,(FirstName, LastName)
或(LastName, FirstName)
的索引也可能很有用。
注意 #2:如果在 final SELECT
子句中有更多列,则此解决方案的性能应该更好。