Hi Shawn,
Thanks for your reply, but your query seems to return everyone allocated to that project plus everyone who has ever been booked on that project. What I need is everyone who is currently allocated to that project and the staff member who has been booked for the booking in question whether they have been allocated to the project or not.
In reply to your quesion bookings don't relate to allocations directly. A booking relates to a project by Project_ID and to a user by User_ID. Allocations contains both of these fields to determine who is 'Allocated' to a particular project.
Thanks again for your help!
From: [EMAIL PROTECTED] To: "shaun thornburgh" <[EMAIL PROTECTED]> CC: mysql@lists.mysql.com,[EMAIL PROTECTED] Subject: Re: Help with a join query please! Date: Thu, 23 Dec 2004 10:14:24 -0500
So -- what's the field that relates a booking to an allocation? Do they share a project_ID or what? If they do, you might try this:
SELECT DISTINCT U.User_ID, U.User_Firstname, U.User_Lastname FROM Users U LEFT JOIN Allocations A on A.User_ID = U.User_ID LEFT JOIN Bookings B ON B.User_ID = U.User_ID WHERE A.Project_ID = '11' OR B.Project_ID = '11' ORDER BY User_Firstname;
<soapbox> A pet peeve of mine is when people 'quote' NUMBERS. According to the extremely well written manual, you only need to quote STRING values and DATETIME values. Unless the columns Project_ID and Booking_ID are some form of STRING column (CHAR, VARCHAR, TEXT, etc.) you don't need to quote their values in queries. It forces the query engine to perform an unnecessary internal type conversion. Here is what I think your query should look like:
SELECT DISTINCT U.User_ID, U.User_Firstname, U.User_Lastname FROM Users U LEFT JOIN Allocations A on A.User_ID = U.User_ID LEFT JOIN Bookings B ON B.User_ID = U.User_ID WHERE A.Project_ID = 11 OR B.Project_ID = 11 ORDER BY User_Firstname; </soapbox>
I used SELECT DISTINCT so that in the event that someone was both BOOKED and ALLOCATED to the same project, you only got them listed once.
Shawn Green Database Administrator Unimin Corporation - Spruce Pine
"shaun thornburgh" <[EMAIL PROTECTED]> wrote on 12/23/2004 08:37:37 AM:
> Hi, > > Thanks for your reply but that produces exactly the same result... > > Any ideas? > > >From: Sasha Pachev <[EMAIL PROTECTED]> > >To: shaun thornburgh <[EMAIL PROTECTED]> > >CC: mysql@lists.mysql.com > >Subject: Re: Help with a join query please! > >Date: Tue, 21 Dec 2004 14:57:43 -0700 > > > >shaun thornburgh wrote: > >>Hi, > >> > >>I have (among others) three tables in my database that i am struggling
> >>with a join query on. The database holds dates for Bookings. If Users are > >>Allocated to a particular Project they can be booked. However if a user is > >>booked but then unallocated I want to be able to display all peolple > >>allocated to that project plus the person originally booked. Here are my > >>efforts so far: > >> > >>SELECT U.User_ID, U.User_Firstname, U.User_Lastname > >>FROM Allocations A, Users U > >>LEFT JOIN Bookings B > >>ON B.User_ID = U.User_ID > >>AND B.Booking_ID = '4512' > >>WHERE U.User_ID = A.User_ID > >>AND A.Project_ID = '11' > >>ORDER BY User_Firstname; > > > >Shaun: > > > >If I understand the problem right, it sounds like you are missing AND > >B.Bookings_ID is NULL in the where clause. > > > > > > > >-- > >Sasha Pachev > >Create online surveys at http://www.surveyz.com/ > > > >-- > >MySQL General Mailing List > >For list archives: http://lists.mysql.com/mysql > >To unsubscribe: > >http://lists.mysql.com/[EMAIL PROTECTED] > > > > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] >
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