Hi Krishnakanth,
There is one layer between application server and data base server called data base interface in sap.Data base interface convert abap open sql statement into corresponding data base select statement so that program is data base independent.So there is minor difference between
abap and sql server select statement. In sap also we can write data base dependent select query called as native sql. For more details http://help.sap.com/saphelp_nw04/helpdata/en/fc/eb3b8b358411d1829f0000e829fbfe/content.htm
In sap we can see converted sql statement by interface in tool called sql trace.
Regards,
Sreenivas.