使用OFFSET-FETCH,如何将行数默认为"所有行"？

Question

设想一个存储过程,它接受@skip(偏移)和@take(要返回的最大行数.如果@take是null,那么我想返回"应用偏移后的所有行".

我可以通过计算表/视图中的行数来实现这@take一点null,但是我必须执行两个查询,这当然不是最佳的.我希望有一个类似的选项FETCH [NEXT] ALL ROWS.

DECLARE @skip BIGINT = 0;
DECLARE @take BIGINT = NULL;

IF (@take IS NULL) SET @take = (SELECT COUNT(*) FROM SomeTable);

SELECT *
FROM SomeTable
ORDER BY SortOrder
OFFSET @skip ROWS
FETCH NEXT @take ROWS ONLY

Answer 1

你可以使用COALESCE:

DECLARE @skip BIGINT = 0;
DECLARE @take BIGINT = NULL;

SELECT *
FROM SomeTable
ORDER BY SortOrder
OFFSET COALESCE(@skip,0) ROWS
FETCH NEXT COALESCE(@take,0x7ffffff) ROWS ONLY

LiveDemo

0x7ffffff与2147483647最大值相同INT.

当提供@skip和@take未提供时,它将从表中获得前2 ^ 31-1条记录.