在第一个表上限制左联接

轻柔的风

我有两个表：gem和gemdetail保持连接状态。我试图将LEFT
JOIN限制为gems表中的10条记录。也有两个其他表联接（gemreply和用户），但它们不会导致该问题。以下内容不起作用：
2 |% ^# {% e: ^8 U3 ]SELECT gems.gemid, gems.title, r.tot, gemdetail.filename FROM ((gems
LEFT JOIN (SELECT gemid, COUNT(*) AS tot FROM gemreply GROUP BY gemid) AS r ON gems.gemid = r.gemid)
LEFT JOIN gemdetail ON gems.gemid = gemdetail.gemid)
LEFT JOIN users ON gems.userid = users.userid
WHERE gems.grade = '7' ORDER BY gems.gemid LIMIT 0, 10;
' |+ Q; M) f8 ]; s& a5 b这将返回的行总数限制为10，但是由于每个gem有多个明细记录，所以我剩下不到10个gem记录。我已经阅读了每个“ LIMIT”帖子，但没有发现这种情况。
更新1：好的-感谢jviladrich-它奏效了。这是代码：
- `  x2 }2 W9 [* z. T) y# R' a' oSELECT gems.gemid, gems.title, r.tot, gemdetail.filename  
FROM ((gems
1 w; d9 V* [# e1 l) H0 k% P% IINNER JOIN (SELECT gems.gemid from gems WHERE gems.grade = '7'  ORDER BY gems.gemid LIMIT 0, 10) g
ON (gems.gemid = g.gemid)
' N2 a8 v4 W7 nLEFT JOIN (SELECT gemid, COUNT(*) AS tot FROM gemreply GROUP BY gemid) AS r ON gems.gemid = r.gemid)
8 N; W& C; R7 K! u7 M& M* e" _LEFT JOIN gemdetail ON gems.gemid = gemdetail.gemid)
" B  m, f5 _2 l: R+ w# C( Z7 DLEFT JOIN users ON gems.userid = users.userid ;
( j! ^; ~6 \; _$ ?; x更新2：yogeshr下面的代码也可以工作-可能是我将要使用的代码。感谢你们俩！
               
/ c% E1 `  X9 Q. k+ D+ D解决方案:
               
$ |7 R* a# ~# |- l) m: [" Q
# j$ z" N& {  C2 i* ?$ k# C
                像这样
+ l* ]9 ?. X3 g   SELECT * FROM A
* b* r( `! K; ^( l& q: a      INNER JOIN ( SELECT * FROM A WHERE A.FIELD1='X' ORDER BY A.FIELD2 LIMIT 10) X
( K( L- d0 O8 B. }: j0 C             ON (A.KEYFIELD=X.KEYFIELD)
7 j! w  C  f& Z6 R5 j      LEFT JOIN B ON (A.FIELD = B.FIELD)
' m. ~, ]2 {1 T9 C! B      LEFT JOIN C ON (A.FIELD = C.FIELD)