Question

我遇到了SQL查询的问题。我有145个站点名称的列表。在每个地点都发现了某些物种。我已经计算了每个地点每个物种被看到的次数。我想找到每个地点看到的5种最常见的物种。目前我有：

SELECT TOP 5 Count([bird point counts bound query].[Group size]) AS [CountOfGroup size], [bird point counts bound query].site, [bird point counts bound query].Species
FROM [bird point counts bound query]
GROUP BY [bird point counts bound query].site, [bird point counts bound query].Species
ORDER BY Count([bird point counts bound query].[Group size]) DESC;

这只是从所有地点返回5种最常见的物种。只是为了澄清，每个站点和145个站点的前5个结果，结果表应该包含725条记录。我现在在Access工作。

任何帮助，因为SQL不是我的强项。

Answer 1

据我所知，你只能在Access中使用临时表来完成这项工作。

这些方面的东西？

CREATE TABLE ##SiteSpecies (
  id            int IDENTITY (1,1),
  Site          <whatever>,
  Species       <whatever>,
  Observations  int
)

INSERT INTO ##SiteSpecies
SELECT   [bird point counts bound query].site, [bird point counts bound query].Species, Count([bird point counts bound query].[Group size])
FROM     [bird point counts bound query]
GROUP BY [bird point counts bound query].site, [bird point counts bound query].Species
ORDER BY [bird point counts bound query].site, [bird point counts bound query].Species, Count([bird point counts bound query].[Group size])

SELECT
  results.*
FROM
  ##SiteSpecies        AS results
INNER JOIN
(
  SELECT Site, MIN(id) AS FirstID FROM ##SiteSpecies GROUP BY Site
)
  AS SiteMarkers
    ON  results.Site  = SiteMarkers.Site
    AND results.id   <= SiteMarkers.FirstID + 4

SQL TOP结果按字段分组

1 个答案: