Ed,
The _expression_ here is '1', which it sums rowwise.That's not really what I meant. I know what the function SUM() does. But Sum() takes an _expression_ and '1' doesn't seem like much of an _expression_ to me. So what is that 1 equates to and where in the MySQL documentation can I find this explained. PB ----- Thanks again.Peter Brawley <[EMAIL PROTECTED]> 4/5/06 10:28 AM >>>Hi Ed, Count(1) works just as well. Sum(1) just adds 1 for each row so it's logically equivalent. PB ----- Ed Reed wrote: WOW!!! THAT WAS AWESOME!!! Thanks a lot Peter. Ok, so what is SUM(1)? How is it able to do this? And where can I learn more about it? Thanks again. Peter Brawley <[EMAIL PROTECTED]> 4/4/06 10:13:00 PM >>> Ed,e: Thanks for the quick reply Peter. Unfortunately, this is all legacy stuff that I have to make work together and the problemreport table does not reference the employeeid in the employees table. It was all create about ten years ago and the data has just always been migrated to the db du jour. I'm currently using MySQL 4.1x but most importantly I must be able to run the entire query in a single call. Thanks for the help. OK, that's doable in a subquery, and you can get the total from SUM(1), so something like ...SELECT IF( SUM(1) = 0, '', CONCAT( 'You have ', SUM(1), ' Problem Report', IF(SUM(1 ) = 1,'','s'), ': Priorities(High=', SUM(IF(Priority='High',1,0)), ',Med=', SUM(IF(Priority='Med',1,0)), ',Low=', SUM(IF(Priority='Low' ,1,0)), ')' ) )FROM ( SELECT Priority FROM ProblemReports, Employees WHERE ProblemReports.Status='Open' AND ProblemReports.Responsible=CONCAT(Employees.FirstName, ' ',Employees.LastName) AND Employees.DateTerminated IS NULL AND Employees.UserName='User1') AS priorities;PB----- Peter Brawley <[EMAIL PROTECTED]> 4/4/06 2:35:49 PM >>> Ed,The big slowdown in your query is likely the join on ProblemReports.Responsible = CONCAT(Employees.FirstName, ' ',Employees.LastName)) Eek. Does the employees table not have a primary key, and does the problemreports table not reference that key? If not, I would think a first priority would be to fix that.Meanwhile, you can simplify your monster query by writing the user's problem priorities to a temp table, then doing a simple pivot on priority to generate your sentence. Something like ...DROP TEMPORARY TABLE IF EXISTS ProbSum;CREATE TEMPORARY TABLE ProbSumSELECT Priority FROM ProblemReports, Employees WHERE ProblemReports.Status='Open' AND ProblemReports.Responsible=CONCAT(Employees.FirstName, ' ',Employees.LastName) AND Employees.DateTerminated IS NULL AND Employees.UserName='User1'SELECT COUNT(*) INTO @n FROM ProbSum;SELECT IF( @n = 0, '', CONCAT( 'You have', @n, 'Problem Report', IF(@n=1,'','s'), ': Priorities(High=', SUM(IF(Priority='High',1,0)), ',Med=', SUM(IF(Priority='Med',1,0)), ',Low=', SUM(IF(Priority='Low' ,1,0)), ')' ) )FROM probsum;DROP TEMPORARY TABLE probsum;All this would be easier in a s tored procedure, if you have MySql 5.PB -----Ed Reed wrote: Can someone help me simplify this query please? It's meant to return a single string result that looks something like this, "You have 12 open Problem Reports: Priorities(High=5, Med=6, Low=1)" The relavent columns from the two tables are Table: ProblemReportsFields: PRNo, Status, Priority, Responsible Table: EmployeesFields: Firstname, Lastname, DateTerminated, UserName Here's the query Select IF((@a:=(SELECT Count(PRNo) From ProblemReports, Employees WHERE (ProblemReports.Status='Open') AND (ProblemReports.Responsible=ConCat(Employees.FirstName, ' ',Employees.LastName)) AND (Employees.DateTerminated Is Null) AND (Employees.UserName='User1')))>0, If (@a=1, ConCat('You have one open Problem Report: Prioritiy = ', (Select Priority From ProblemReports, Employees WHERE (ProblemReports.Status='Open') AND (ProblemReports.Responsible=ConCat(Employees.FirstName, ' ',Employees.LastName)) AND (Employees.DateTerminated I s Null) AND (Employees.UserName='User1'))), Concat('You have ', @a, ' open Problem Reports: Priorities(', (Select ConCat('High=',Count(Priority)) From ProblemReports, Employees WHERE (ProblemReports.Status='Open') AND (ProblemReports.Responsible=ConCat(Employees.FirstName, ' ',Employees.LastName)) AND (Employees.DateTerminated Is Null) AND (Employees.UserName='User1') And (Priority='High')),', ',(Select ConCat('Med=',Count(Priority)) From ProblemReports, Employees WHERE (ProblemReports.Status='Open') AND (ProblemReports.Responsible=ConCat(Employees.FirstName, ' ',Employees.LastName)) AND (Employees.DateTerminated Is Null) AND (Employees.UserName='User1') And (Priority='Med')),', ',(Select ConCat('Low=',Count(Priority)) From ProblemReports, Employees WHERE (ProblemReports.Status='Open') AND (ProblemReports.Responsible=ConCat(Employees.FirstName, ' ',Employees.LastName)) AND (Employees.DateTerminated Is Null) AND (Employees.UserName='User1') And (Priority='Low')),')')),''); No virus found in this incoming message.Checked by AVG Free Edition.Version: 7.1.385 / Virus Database: 268.3.5/300 - Release Date: 4/3/2006 No virus found in this incoming message.Checked by AVG Free Edition.Version: 7.1.385 / Virus Database: 268.3.5/300 - Release Date: 4/3/2006 No virus found in this incoming message.Checked by AVG Free Edition.Version: 7.1.385 / Virus Database: 268.3.5/301 - Release Date: 4/4/2006 |
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