SQLServerCentral / SQL Server 2008 / SQL Server Newbies / Group by and Where clause / Latest PostsInstantForum.NET v2.9.0SQLServerCentralhttp://www.sqlservercentral.com/Forums/notifications@sqlservercentral.comWed, 22 May 2013 04:39:01 GMT20RE: Group by and Where clausehttp://www.sqlservercentral.com/Forums/Topic1425968-1292-1.aspx[url]http://sqlblog.com/blogs/paul_white/archive/2012/03/12/fun-with-aggregates.aspx[/url]Mon, 04 Mar 2013 00:43:34 GMTGilaMonsterRE: Group by and Where clausehttp://www.sqlservercentral.com/Forums/Topic1425968-1292-1.aspxThanks for your reply Jeff.I got clear pic .. thanks a lot...one more doubt Jeff,both the condition table is empty,then why the where condition returns 'null'and group by condition returns nothing.can you plz explain me ?Sun, 03 Mar 2013 23:04:47 GMTsanandh87RE: Group by and Where clausehttp://www.sqlservercentral.com/Forums/Topic1425968-1292-1.aspxIn the first query, you give SQL Server no choice. You say to find the MAX unconditionally for the given criteria and there isn't one so it returns a NULL.In the second query, it's different. You're saying find the MAX for a given group which is actually a condition. There are no groups that match your criteria so it returns nothing.Sun, 03 Mar 2013 20:33:34 GMTJeff ModenGroup by and Where clausehttp://www.sqlservercentral.com/Forums/Topic1425968-1292-1.aspxHi,Please see below, Table name : Log_tableColumns: Logid int, databasename varchar(30), tablename varchar(30), logdate datetimeQuery 1: Select max(logdate) from log_table where databasename='db1' and tablename='table1';consider the Log_table is empty, when I execute Query 1, the result will be 'Null'.Query 2 : select max(logdate) from log_table Where databasename='db1' and tablename='table1' group by databasename,tablename;Consider the log_table is empty, when I execute Query 2, the result will be empty.Note : both the condition table is empty.Please explain me what happening inside and why the result different?Sun, 03 Mar 2013 09:47:06 GMTsanandh87