MySQL 如何在 SQL 中的另一个选择中编写选择语句
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How to write a select statement inside another select in SQL
提问by Faryal Khan
Can anyone tell me what is wrong with this query? it gives a syntax error near the 2nd select
谁能告诉我这个查询有什么问题？它在第二个选择附近给出了语法错误
SELECT b.mc_boxes_idmc_boxes,
t.idtitles,
t.title,
t.languages_idlanguages,
MAX(h.idtitle_history),
MAX(h.edition)
(SELECT h.preview, h.file WHERE h.idtitle_history = MAX(h.idtitle_history))
FROM mc_boxes_has_titles b
LEFT JOIN titles t ON b.titles_idtitles = t.idtitles
LEFT JOIN title_history h ON h.titles_idtitles = t.idtitles
WHERE b.mc_boxes_idmc_boxes = 12
AND h.edition IS NOT NULL
GROUP BY b.mc_boxes_idmc_boxes, idtitles
ORDER BY b.sortorder;
回答by Taryn
looks like you are missing a comma after MAX(h.edition)
看起来你后面缺少一个逗号 MAX(h.edition)
SELECT b.mc_boxes_idmc_boxes,
t.idtitles,
t.title,
t.languages_idlanguages,
MAX(h.idtitle_history),
MAX(h.edition),
(SELECT h.preview, h.file WHERE h.idtitle_history = MAX(h.idtitle_history))
FROM mc_boxes_has_titles b
LEFT JOIN titles t ON b.titles_idtitles = t.idtitles
LEFT JOIN title_history h ON h.titles_idtitles = t.idtitles
WHERE b.mc_boxes_idmc_boxes = 12
AND h.edition IS NOT NULL
GROUP BY b.mc_boxes_idmc_boxes, idtitles
ORDER BY b.sortorder;
besides the comma, you are selecting two fields in your subquery
除了逗号之外，您还要在子查询中选择两个字段
SELECT b.mc_boxes_idmc_boxes,
t.idtitles,
t.title,
t.languages_idlanguages,
MAX(h.idtitle_history),
MAX(h.edition),
(SELECT preview FROM title_history WHERE idtitle_history = MAX(h.idtitle_history)),
(SELECT [file] FROM title_history WHERE idtitle_history = MAX(h.idtitle_history))
FROM mc_boxes_has_titles b
LEFT JOIN titles t ON b.titles_idtitles = t.idtitles
LEFT JOIN title_history h ON h.titles_idtitles = t.idtitles
WHERE b.mc_boxes_idmc_boxes = 12
AND h.edition IS NOT NULL
GROUP BY b.mc_boxes_idmc_boxes, idtitles
ORDER BY b.sortorder;
回答by Otávio Décio
Adding to bluefeet's answer, you may want to check for reserved words. "File" for example is a reserved word in sql server.
添加到 bluefeet 的答案中，您可能需要检查保留字。例如，“文件”是 sql server 中的保留字。
回答by Hamza Waqas
Alias it as a virtual table. Change something like
将其别名为虚拟表。改变类似的东西
SELECT b.mc_boxes_idmc_boxes,
t.idtitles,
t.title,
t.languages_idlanguages,
MAX(h.idtitle_history),
MAX(h.edition)
(SELECT h.preview, h.file WHERE h.idtitle_history = MAX(h.idtitle_history))
FROM mc_boxes_has_titles b
LEFT JOIN titles t ON b.titles_idtitles = t.idtitles
LEFT JOIN title_history h ON h.titles_idtitles = t.idtitles
WHERE b.mc_boxes_idmc_boxes = 12
AND h.edition IS NOT NULL
GROUP BY b.mc_boxes_idmc_boxes, idtitles
ORDER BY b.sortorder) as virtual_column_alias;
Check this out. Hope this will work.
看一下这个。希望这会奏效。
