select ステートメントに参加しようとしています。しかし、サブクエリの選択は非常に多くの行を返し、非常に遅くなります-最初の選択からサブクエリへのIDを取得できないためです。
エラーは次のとおりです。
エラー コード: 1054。「where 句」の列「ritzau_data.News.id」が不明です
最初の選択でこのIDを結合内の選択に取得するにはどうすればよいですか? 私はMSSQLで似たようなものを作りました - それはうまくいきます。動作中の MSSQL コードも貼り付けます。
MySQLCode (動作していません):
select News.id as newsid, header as title, content as contents, created as published_time, 2883 as drupalid, isins, categories, NewsTypes.npName from ritzau_data.News,
(
select idNews, group_concat(isin separator ', ') as isins
from ritzau_data.NewsIsin
where idNews = ritzau_data.News.id
group by idNews
) as isins,
(
select idNews, group_concat(distinct Category separator ', ') as categories
from ritzau_data.NewsTags
inner join ritzau_data.TagsCategoriesMap on NewsTags.idTag = TagsCategoriesMap.idTags
inner join ritzau_data.Categories on TagsCategoriesMap.idCategories = Categories.id
where idNews = ritzau_data.News.id
group by idNews
) as categories
left join ritzau_data.NewsTypes on News.idType = NewsTypes.id
inner join ritzau_data.NewsReceivers on News.id = NewsReceivers.idNews
where ritzau_data.News.id > 100 and idReceiver = 3
order by News.id
limit 100;
MSSQLCode (動作中):
SELECT TOP 1000 news.id AS newsid,
cast(title as varchar(256)) AS title, cast(contents as text)AS contents, published_time, users.drupalid,
cast (STUFF(
(
SELECT ',' + isin
FROM news_instruments t1
left join instruments t2 on t1.instrument_id = t2.id
where news_id = news.id
FOR XML PATH('')
),1,1,''
) as text) AS isins,
cast(STUFF(
(
SELECT ',' + t2.name
FROM news_categories t1
left join categories t2 on t1.category_id = t2.id
where news_id = news.id
FOR XML PATH('')
),1,1,''
) as text) AS categories
from news
left join users on news.locked_userid = users.id
where news.id > @offsetid
最初のクエリ - 動作しますが、非常に遅いです
select News.id as newsid, header as title, content as contents, created as published_time, 2883 as drupalid, isins, categories, NewsTypes.npName from ritzau_data.News
left join ritzau_data.NewsTypes on News.idType = NewsTypes.id
inner join ritzau_data.NewsReceivers on News.id = NewsReceivers.idNews
select idNews, group_concat(isin separator ', ') as isins
from ritzau_data.NewsIsin
where idNews = News.id
group by idNews
) as isins on News.id = isins.idNews
left join (
select idNews, group_concat(distinct Category separator ', ') as categories
from ritzau_data.NewsTags
inner join ritzau_data.TagsCategoriesMap on NewsTags.idTag = TagsCategoriesMap.idTags
inner join ritzau_data.Categories on TagsCategoriesMap.idCategories = Categories.id
where idNews = News.id
group by idNews
) as categories on News.id = categories.idNews
where News.id > @idoffset and idReceiver = 3
order by News.id
limit 100;