There might not be a performance penalty, this is a long ago practice of mine from the wilds of SQL 6.5. Also the syntax Mike used in MS SQL syntax and not ANSI. Not a big point since few people port SQL code, but I also find the ANSI easier to understand when there is a complex query wiht many tables.
This SQL site has some good stuff.. http://www.sql-server-performance.com/tuning_joins.asp On Tue, 1 Feb 2005 22:08:57 -0600, Peter Brunone <[EMAIL PROTECTED]> wrote: > > > Interesting. I had no idea there was a performance difference > between the two (but then again, DB architecture isn't my forte). Any > recommended reading on this? > > -----Original Message----- > From: Dean Fiala [mailto:[EMAIL PROTECTED] > > No, he's using the WHERE clause to perform the join. It works, but it > is a bad habit to get into, and doesn't scale well (maintenance wise, > and possibly performance wise) when used with a larger number of tables. > > On Tue, 1 Feb 2005 21:16:38 -0600, Peter Brunone > <[EMAIL PROTECTED]> wrote: > > > > > > Isn't he using an inner join already? > > > > -----Original Message----- > > From: Dean Fiala [mailto:[EMAIL PROTECTED] > > > > Use an alias on at least one of the columns in your select statment, > > that is what is causing the ambiguous column name. > > > > Also you would be better served using an inner join, though that is > > not the issue. > > > > Select table1.username t1User, table2.username t2User > > FROM table1 inner join table2 on table1.accountNum = table2.accountNum > > > > On Tue, 1 Feb 2005 16:48:19 -0500, Mike Appenzellar > > <[EMAIL PROTECTED]> wrote: > > > > > > I have a query with multiple tables, that being said there is the > > > same > > > > > field in both tables...ex: > > > > > > Select table 1.username, table 2.accountNum > > > FROM table 1, table 2 > > > WHERRE table 1.accountNum = table 2.accountNum > > > > > > table 1 > > > - id > > > - accountNum > > > - username > > > > > > table2 > > > - id > > > - accountNum > > > - name > > > > > > When I bind the query to a datagrid, I get "Ambiguous column name". > > > Any ideas? > > Yahoo! Groups Links > > > > > -- Dean Fiala Very Practical Software, Inc http://www.vpsw.com Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/AspNetAnyQuestionIsOk/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
