select a.* from YG_BRSYK a
left join(SELECT DISTINCT SYXH,
STUFF((SELECT '、'+MS FROM #lsb where SYXH=t.SYXH FOR XML PATH('')),1,1,'') AS MS
FROM #lsb as t) c on a.SYXH=c.SYXH WHERE c.MS IS NOT NULL order by RYBQ
--注：left join...on 為左關聯，保留左邊所有的數據，右表沒有的數據為NULL值。加where條件控制表的輸出C.MS不為NULL。因此查詢的個數與c表一致760個
select a.* from YG_BRSYK a --801331個
SELECT DISTINCT SYXH,
STUFF((SELECT '、'+MS FROM #lsb where SYXH=t.SYXH FOR XML PATH('')),1,1,'') AS MS
FROM #lsb as t 670個
https://www.cnblogs.com/lcs-java/articles/8465605.html
t1表內容如下：
t2表內容如下：
下面來簡述join和left join/right join的區別：
inner join
select * from t1 inner join t2 on t1.id = t2.id;
公共部分的數據才會被查詢出來；
left join
select * from t1 left join t2 on t1.id = t2.id;
查詢出來的結果和前表記錄數一樣多；
right join
select * from t1 right join t2 on t1.id = t2.id;
能轉化為