Is there any method in java using which we can find which database we are using....let me elaborate.. I am writing a java code which will query a database.. there are two databases..SQL server and Oracle ....and I have two different SQL statement for these...I have to decide from the program which database I am using and use the appropriate SQL statement in the program... So is there any system call to do this? Thanks
No. What are the rules which define which database you are using? Normally this would be a configuration issue and some flag or property would direct the code which to use.
Hi paul my problem is I have two statements which do the same thing.
oracle version:
select u.useraccountid,u.personid,u.useraccountnm,u.passwordtxt from PRSNACCSASSIGN p,USERACCOUNT
u,PERSONSTATUSMM ps where p.MGRACCESSLASID <> -2 and u.useraccountid > 0 and ps.EmploymentStatID = 1 And ps.UserAcctStatID =
1 And ps.ExpirationDTM >= to_date('03/03/2005', 'mm/dd/yyyy') and ps.EffectiveDTM <= to_date('03/03/2005', 'mm/dd/yyyy') and u.personid = p.personid and ps.personid = p.personid
SQL server version:
select u.useraccountid,u.personid,u.useraccountnm,u.passwordtxt from PRSNACCSASSIGN p,USERACCOUNT
u,PERSONSTATUSMM ps where p.MGRACCESSLASID <> -2 and u.useraccountid > 0 and ps.EmploymentStatID = 1 And ps.UserAcctStatID =
1 And ps.ExpirationDTM >= '03/03/2005' and ps.EffectiveDTM <= '03/03/2005' and u.personid = p.personid and ps.personid = p.personid
I want to give my program enough flexibily so that the user does not have to choose from these statements..the program should do it.
The two queries you've highlighted are identical in all but one respect - how you've chosen to handle the dates. If you rewrote the query to use a PreparedStatement and bind the date value as a Date object then you can use this on both DBs transparently.
If you find yourself worrying about the effect of DB specific SQL finding its way into your application then I suggest you read up on the DAO pattern.
Neel Chow
Ranch Hand
Joined: Jan 10, 2005
Posts: 55
posted
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Thanks Paul..
I agree. Here's the link: http://ej-technologies/jprofiler - if it wasn't for jprofiler, we would need to
run our stuff on 16 servers instead of 3.
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