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我想知道如何有条件地使用函数参数。这是我的函数，您可以阅读查询中的注释：

CREATE OR REPLACE FUNCTION mediabase.select_media(sysEnvironment character varying, statusId integer)
RETURNS refcursor AS
$BODY$
DECLARE
  ref refcursor; 
BEGIN
  OPEN ref FOR 

  SELECT media.id, media.title, media.unique_filename, media.owner_id, media.status_id, media.location_name_id, media.upload_user_id, media.upload_ip, media.metadata_id, media.type_id, media.description, media.system_environment, media.upload_date, media.gps_location, media.language_id, media_publications.publication_id, media.limitations, media_categories.category_id, metadata.width, metadata.height, metadata.equipment, metadata.copyright, metadata.creation_time, metadata.file_format, metadata.resolution, metadata.resolution_unit, metadata.gps_longitude, metadata.gps_latitude, metadata.artist, metadata.color_space, metadata.gps_altitude, metadata.software_used, metadata.user_comment
  FROM mediabase.media, mediabase.metadata, mediabase.media_categories, mediabase.media_publications
  WHERE media.metadata_id = metadata.id
  AND media.id = media_categories.media_id
  AND media.id = media_publications.media_id
  -- Problem: this CASE doesn't work of course
  CASE statusId <> -1 THEN
    AND media.status_Id = statusId
  END
  -- End problem
  AND media.system_environment = sysEnvironment
  ORDER BY media.upload_date DESC;

  RETURN ref;                       
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;

我只需要使用'statusId'参数，如果它不同于-1，否则我将不会收到任何结果，因为当然没有状态-1。稍后，我需要添加更多此类过滤器。

4

1 回答 1

1

尝试类似：

AND (media.status_Id = statusId OR statusId = -1)

它不会检查media.status_Id = statusId是否statusId = -1。

于 2013-01-15T12:29:05.023 回答