[英]RowNumber() Over(Order By x) with a subquery not working
The 'count' query runs fine. “计数”查询运行良好。 The 'Page of records' query runs fine as long as the commented section stays as-is.
只要注释部分保持原样,“记录页面”查询就可以正常运行。 If uncommented it never returns... just keeps going.
如果不加注释,它将永远不会返回...继续前进。 Any help on how to get past this would be greatly appreciated.
任何帮助如何克服这一困难将不胜感激。
-- Page or records
DECLARE @p0 int;
DECLARE @p1 int;
SET @p0 = 100;
SET @p1 = 20;
SELECT DISTINCT ZIP_CODE, RowNum
FROM ( SELECT ROW_NUMBER() OVER (ORDER BY ZIP_CODE) as RowNum, ZIP_CODE
FROM ODS.PHP1300_DWH.FACETS_MEMBER
--WHERE LEFT(ZIP_CODE, 5) NOT IN (SELECT SHORT_ZIP_CODE
-- FROM DWH.Reference.R_ZIP_CODE)
) AS x
WHERE RowNum BETWEEN @p0 + 1 AND @p0 + @p1
ORDER BY RowNum
-------------------------------------------------------------------------------------
-- Count
SELECT COUNT(ZIP_CODE)
FROM ODS.PHP1300_DWH.FACETS_MEMBER
WHERE LEFT(ZIP_CODE, 5) NOT IN (SELECT SHORT_ZIP_CODE
FROM DWH.Reference.R_ZIP_CODE)
I think that your predicate in the derived table is just quite expensive. 我认为您在派生表中的谓词非常昂贵。 Hard to say without an execution plan.
没有执行计划很难说。 Here are a couple of measures you can take:
您可以采取以下几种措施:
LEFT(FACETS_MEMBER.ZIP_CODE, 5)
a computed column and index it LEFT(FACETS_MEMBER.ZIP_CODE, 5)
成为计算列并为其编制索引 R_ZIP_CODE.SHORT_ZIP_CODE
has an index on it R_ZIP_CODE.SHORT_ZIP_CODE
有索引 R_ZIP_CODE.SHORT_ZIP_CODE
has a NOT NULL
constraint on it. R_ZIP_CODE.SHORT_ZIP_CODE
具有NOT NULL
约束。 Apart from that, I think that your DISTINCT
keyword in the outer query is useless, as you're adding the RowNum
, which is distinct for every record anyway. 除此之外,我认为您在外部查询中使用的
DISTINCT
关键字是无用的,因为您要添加RowNum
,无论如何,这对于每条记录都是不同的。 So you should move DISTINCT
into your nested query, which should use DENSE_RANK()
instead of ROW_NUMBER()
, as explained here: 因此,您应该将
DISTINCT
移到嵌套查询中,该查询应使用DENSE_RANK()
而不是ROW_NUMBER()
,如此处所述:
http://blog.jooq.org/2013/10/09/sql-trick-row_number-is-to-select-what-dense_rank-is-to-select-distinct/ http://blog.jooq.org/2013/10/09/sql-trick-row_number-is-to-select-what-dense_rank-is-to-select-distinct/
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