Http://www.cnblogs.com/pcsky/archive/2004/10/27/57449.Html Multi-Table Connection SQL Writing (SQLServer, Oracle)
Oracle8
Select a. *, b. * from a, b where A.ID ( ) = B.ID - equivalent to the left
Select a. *, b. * from a, b where a.id = B.ID ( ) - equivalent to the right connection
Oracle9
Support for the above writing, also adding Leftjoin, Right Join, etc.
Select a. *, b. * from a left join b on a.id = B.ID
Select a. *, b. * from a right join b on A.Id = B.ID
SQLServer
Select a. *, b. * from a, b where A.id * = B.ID - equivalent to the left
Select a. *, b. * from a, b where a.id = * B.ID - equivalent to the right connection
Select a. *, b. * from a left join b on a.id = B.ID
Select a. *, b. * from a right join b on A.Id = B.ID
