1. åæ¥è¯¢æ¹æ³
select *
from DB2.table2
where å段 in (select table1ä¸ç¸åºå段 from DB1.table1 where table1ä¸ç¸åºå段=ç¸åºå¼)
2. å·¦è¿æ¥æ¹æ³
select table2.*
from DB2.table2 left join DB1.table1
on table1.å段 = table2.ç¸åºå段
where table2.ç¸åºå段 = ç¸åºå¼;
2. 交åè¿æ¥æ¹æ³
select table2.*
from DB2.table2, DB1.table1
where table1.å段 = table2.ç¸åºå段 and table2.ç¸åºå段 = ç¸åºå¼;
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