获取从查询返回的总mysql结果时有一个限制：FOUND\u ROWS错误

我有一个mysql查询：

SELECT Files.GUID, Files.Name, Files.Type, Files.Visibility, Files.CreationDate, Files.OwnerUser, Date, BackupsCount
FROM Files
  LEFT JOIN (
    SELECT FileGUID, Date, COUNT(*) AS BackupsCount
    FROM Versions
    GROUP BY FileGUID
  ) Versions ON Files.GUID = Versions.FileGUID
WHERE Files.ParentFolder = '96251A8B-B2A8-416B-92D7-3509E6A645C7'
ORDER BY Files.Type DESC, CreationDate ASC
LIMIT 0, 50

我想知道如果LIMIT指令不存在，这个查询将返回多少条记录，我在谷歌上搜索发现我需要添加SELECT SQL\u CALC\u found\u行和SELECT found\u行

我的问题是：我无法让它工作：

SELECT SQL_CALC_FOUND_ROWS * FROM (
SELECT Files.GUID, Files.Name, Files.Type, Files.Visibility, Files.CreationDate, Files.OwnerUser, Date, BackupsCount
FROM Files
  LEFT JOIN (
    SELECT FileGUID, Date, COUNT(*) AS BackupsCount
    FROM Versions
    GROUP BY FileGUID
  ) Versions ON Files.GUID = Versions.FileGUID
WHERE Files.ParentFolder = '96251A8B-B2A8-416B-92D7-3509E6A645C7'
ORDER BY Files.Type DESC, CreationDate ASC
LIMIT 0, 50)

-- Find total rows
SELECT FOUND_ROWS()

---

假设这是一个好主意，我的意思是执行一个查询而不是两个单独的查询，我如何才能让找到的行处理此查询？

查询应如下所示：

SELECT SQL_CALC_FOUND_ROWS Files.GUID, Files.Name, Files.Type, Files.Visibility, Files.CreationDate, Files.OwnerUser, Date, BackupsCount
FROM Files
  LEFT JOIN (
    SELECT FileGUID, Date, COUNT(*) AS BackupsCount
    FROM Versions
    GROUP BY FileGUID
  ) Versions ON Files.GUID = Versions.FileGUID
WHERE Files.ParentFolder = '96251A8B-B2A8-416B-92D7-3509E6A645C7'
ORDER BY Files.Type DESC, CreationDate ASC
LIMIT 0, 50

---

这个想法是正确的，第二个查询几乎是即时的。但您必须在选择后添加关键字，不再添加：

SELECT Files.GUID, Files.Name, Files.Type, ...

变成

SELECT SQL_CALC_FOUND_ROWS Files.GUID, Files.Name, Files.Type, ...

然后将填充找到的行数，您将能够恢复它

如果要运行单个检索查询，但可以执行多个查询，则可以执行两个查询：

SELECT COUNT(*) INTO @FOUNDROWS FROM ( YOUR_QUERY_WITHOUT_SELECT ) AS orig;

SELECT ALL_YOUR_FIELDS, counter.FOUND_ROW_NUMBER FROM
( YOUR_QUERY_WITH_LIMIT ) AS limited
JOIN ( SELECT COUNT(*) AS FOUND_ROW_NUMBER FROM YOUR_QUERY ) AS counter;

并通过将@FOUNDROWS作为FOUNDROWS添加到字段来更改检索查询：

SELECT ...YOUR FIELDS..., @FOUNDROWS AS foundrows FROM...

最后，您可以将联接作为包含以下两个查询的单个查询运行：

SELECT COUNT(*) INTO @FOUNDROWS FROM ( YOUR_QUERY_WITHOUT_SELECT ) AS orig;

SELECT ALL_YOUR_FIELDS, counter.FOUND_ROW_NUMBER FROM
( YOUR_QUERY_WITH_LIMIT ) AS limited
JOIN ( SELECT COUNT(*) AS FOUND_ROW_NUMBER FROM YOUR_QUERY ) AS counter;

---

谢谢，但是查询仍然只返回行，而我需要行数和总计数。您可以通过执行以下操作获得计数：选择第一次查询之后的已找到的行数谢谢，但我仍然需要行数和总计数。我的意思是添加SELECT SQL\u CALC\u FOUND\u行在我运行它时没有显示总计数否，它不会；它只存储计数，然后您必须在第二个查询中检索它。您可以在一个查询中完成，但这将花费您。。。我会努力改进我的答案。