Re: Query returns to many results
Peter Brawley wrote: /Now this query is run over two tables and the ab_members table contains around 302 rows. Around 1/3 of these will be where cup=kids. However, when this query is run it returns 20,700 results / That's because your ... FROM ab_leader_board ablb, ab_members abm calls for a cross join--it asks for every logically possible combination of ablb and abm rows. From the rest of your query, it appears you need something like ... FROM ab_leader_board ablb INNER JOIN ab_members abm USING (name_of_joining_column) Also, do you really mean to sum all those ablb column values after having already called for all ablb column values with ablb.* ? PB - Schalk wrote: Greetings All, Please have a look at the following query: SELECT abm.mem_number, abm.first_name, abm.last_name, abm.area_represented, abm.age, abm.sex, abm.cup, ablb.*, ablb.jp + ablb.rc + ablb.fsmgp + ablb.gmc + ablb.saly + ablb.nwgp + ablb.ecgp + ablb.sams + ablb.wcc + ablb.kzngp + ablb.emc + ablb.lmgp + ablb.saff + ablb.gmgp + ablb.safy + ablb.mmw + ablb.lc + ablb.mmc + ablb.nwmc + ablb.ncc + ablb.samp + ablb.gsc + ablb.wcmgp + ablb.sapm + ablb.kznc + ablb.npc + ablb.smc + ablb.ecc + ablb.mgp + ablb.samo + ablb.cofc + ablb.cs + ablb.ncmgp + ablb.fsc + ablb.ggp + ablb.tmc + ablb.gc + ablb.yotm AS total_points FROM ab_leader_board ablb, ab_members abm WHERE abm.sex = 'Female' AND abm.cup = 'kids' ORDER BY total_points DESC Now this query is run over two tables and the ab_members table contains around 302 rows. Around 1/3 of these will be where cup=kids. However, when this query is run it returns 20,700 results :0 Any idea why this is? Also, any help or pointers as to how I can optimize this query will be much appreciated. Thank you! Greetings Peter, Well, with regards to the ablb.*, I need access to each individual column as well as to the sum of all of those columns, so I think I need to do both, or don't I? -- Kind Regards Schalk Neethling Web Developer.Designer.Programmer.President Volume4.Business.Solution.Developers -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Query returns to many results
Greetings All, Please have a look at the following query: SELECT abm.mem_number, abm.first_name, abm.last_name, abm.area_represented, abm.age, abm.sex, abm.cup, ablb.*, ablb.jp + ablb.rc + ablb.fsmgp + ablb.gmc + ablb.saly + ablb.nwgp + ablb.ecgp + ablb.sams + ablb.wcc + ablb.kzngp + ablb.emc + ablb.lmgp + ablb.saff + ablb.gmgp + ablb.safy + ablb.mmw + ablb.lc + ablb.mmc + ablb.nwmc + ablb.ncc + ablb.samp + ablb.gsc + ablb.wcmgp + ablb.sapm + ablb.kznc + ablb.npc + ablb.smc + ablb.ecc + ablb.mgp + ablb.samo + ablb.cofc + ablb.cs + ablb.ncmgp + ablb.fsc + ablb.ggp + ablb.tmc + ablb.gc + ablb.yotm AS total_points FROM ab_leader_board ablb, ab_members abm WHERE abm.sex = 'Female' AND abm.cup = 'kids' ORDER BY total_points DESC Now this query is run over two tables and the ab_members table contains around 302 rows. Around 1/3 of these will be where cup=kids. However, when this query is run it returns 20,700 results :0 Any idea why this is? Also, any help or pointers as to how I can optimize this query will be much appreciated. Thank you! -- Kind Regards Schalk Neethling Web Developer.Designer.Programmer.President Volume4.Business.Solution.Developers -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Query returns to many results
Schalk , You need to specify the unifying column between your ablb and abm tables. ie - in your where, and ablb.id=abm.id Once you get this so it returns expected results, you can run the query, prefaced with explain and it will give you an idea on the way mysql is running the query. This has helped me determine some additional indexes that greatly speed up my queries. -- George - Original Message - From: Schalk [EMAIL PROTECTED] To: mysql@lists.mysql.com Sent: Thursday, February 23, 2006 6:59 AM Subject: Query returns to many results Greetings All, Please have a look at the following query: SELECT abm.mem_number, abm.first_name, abm.last_name, abm.area_represented, abm.age, abm.sex, abm.cup, ablb.*, ablb.jp + ablb.rc + ablb.fsmgp + ablb.gmc + ablb.saly + ablb.nwgp + ablb.ecgp + ablb.sams + ablb.wcc + ablb.kzngp + ablb.emc + ablb.lmgp + ablb.saff + ablb.gmgp + ablb.safy + ablb.mmw + ablb.lc + ablb.mmc + ablb.nwmc + ablb.ncc + ablb.samp + ablb.gsc + ablb.wcmgp + ablb.sapm + ablb.kznc + ablb.npc + ablb.smc + ablb.ecc + ablb.mgp + ablb.samo + ablb.cofc + ablb.cs + ablb.ncmgp + ablb.fsc + ablb.ggp + ablb.tmc + ablb.gc + ablb.yotm AS total_points FROM ab_leader_board ablb, ab_members abm WHERE abm.sex = 'Female' AND abm.cup = 'kids' ORDER BY total_points DESC Now this query is run over two tables and the ab_members table contains around 302 rows. Around 1/3 of these will be where cup=kids. However, when this query is run it returns 20,700 results :0 Any idea why this is? Also, any help or pointers as to how I can optimize this query will be much appreciated. Thank you! -- Kind Regards Schalk Neethling Web Developer.Designer.Programmer.President Volume4.Business.Solution.Developers -- 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]
Re: Query returns to many results
George Law wrote: Schalk , You need to specify the unifying column between your ablb and abm tables. ie - in your where, and ablb.id=abm.id Once you get this so it returns expected results, you can run the query, prefaced with explain and it will give you an idea on the way mysql is running the query. This has helped me determine some additional indexes that greatly speed up my queries. -- George - Original Message - From: Schalk [EMAIL PROTECTED] To: mysql@lists.mysql.com Sent: Thursday, February 23, 2006 6:59 AM Subject: Query returns to many results Greetings All, Please have a look at the following query: SELECT abm.mem_number, abm.first_name, abm.last_name, abm.area_represented, abm.age, abm.sex, abm.cup, ablb.*, ablb.jp + ablb.rc + ablb.fsmgp + ablb.gmc + ablb.saly + ablb.nwgp + ablb.ecgp + ablb.sams + ablb.wcc + ablb.kzngp + ablb.emc + ablb.lmgp + ablb.saff + ablb.gmgp + ablb.safy + ablb.mmw + ablb.lc + ablb.mmc + ablb.nwmc + ablb.ncc + ablb.samp + ablb.gsc + ablb.wcmgp + ablb.sapm + ablb.kznc + ablb.npc + ablb.smc + ablb.ecc + ablb.mgp + ablb.samo + ablb.cofc + ablb.cs + ablb.ncmgp + ablb.fsc + ablb.ggp + ablb.tmc + ablb.gc + ablb.yotm AS total_points FROM ab_leader_board ablb, ab_members abm WHERE abm.sex = 'Female' AND abm.cup = 'kids' ORDER BY total_points DESC Now this query is run over two tables and the ab_members table contains around 302 rows. Around 1/3 of these will be where cup=kids. However, when this query is run it returns 20,700 results :0 Any idea why this is? Also, any help or pointers as to how I can optimize this query will be much appreciated. Thank you! Thanks George! It works perfectly. Now to optimize this bugger. -- Kind Regards Schalk Neethling Web Developer.Designer.Programmer.President Volume4.Business.Solution.Developers -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Query returns to many results
Schalk [EMAIL PROTECTED] wrote on 02/23/2006 08:55:01 AM: George Law wrote: Schalk , You need to specify the unifying column between your ablb and abm tables. ie - in your where, and ablb.id=abm.id Once you get this so it returns expected results, you can run the query, prefaced with explain and it will give you an idea on the way mysql is running the query. This has helped me determine some additional indexes that greatly speed up my queries. -- George - Original Message - From: Schalk [EMAIL PROTECTED] To: mysql@lists.mysql.com Sent: Thursday, February 23, 2006 6:59 AM Subject: Query returns to many results Greetings All, Please have a look at the following query: SELECT abm.mem_number, abm.first_name, abm.last_name, abm.area_represented, abm.age, abm.sex, abm.cup, ablb.*, ablb.jp + ablb.rc + ablb.fsmgp + ablb.gmc + ablb.saly + ablb.nwgp + ablb.ecgp + ablb.sams + ablb.wcc + ablb.kzngp + ablb.emc + ablb.lmgp + ablb.saff + ablb.gmgp + ablb.safy + ablb.mmw + ablb.lc + ablb.mmc + ablb.nwmc + ablb.ncc + ablb.samp + ablb.gsc + ablb.wcmgp + ablb.sapm + ablb.kznc + ablb.npc + ablb.smc + ablb.ecc + ablb.mgp + ablb.samo + ablb.cofc + ablb.cs + ablb.ncmgp + ablb.fsc + ablb.ggp + ablb.tmc + ablb.gc + ablb.yotm AS total_points FROM ab_leader_board ablb, ab_members abm WHERE abm.sex = 'Female' AND abm.cup = 'kids' ORDER BY total_points DESC Now this query is run over two tables and the ab_members table contains around 302 rows. Around 1/3 of these will be where cup=kids. However, when this query is run it returns 20,700 results :0 Any idea why this is? Also, any help or pointers as to how I can optimize this query will be much appreciated. Thank you! Thanks George! It works perfectly. Now to optimize this bugger. -- Kind Regards Schalk Neethling Web Developer.Designer.Programmer.President Volume4.Business.Solution.Developers Schalk, You wouldn't have even run into this as an issue if you had used the explicit JOIN form. Again, I blame the documentation for only demonstrating the lazy form of INNER JOIN declaration almost exclusively. I believe that by only demonstrating the comma-separated join, they have created the impression that it is a preferred method. I strongly discourage the use of that form of declaring table joins for the very reason you posted. If you had used the explicit form: SELECT ...(all of your columns)... FROM ab_leader_board ablb INNER JOIN ab_members abm ON ablb.id=abm.id (or whatever is appropriate) WHERE ... It should have be intuitively obvious that you had left out the ON clause from your original query. As it was, your missing JOIN conditions were just not noticed because of all of the other activity in your whole statement. This is a very frequent problem with the join syntax you used in your original query. Again, I implore all SQL coders to use the explicit JOIN syntax on all platforms that support it (Oracle being a well-known exception). It makes it much easier to catch logical errors just like Schalk ran into in his original post. The explicit form is also the only way to declare outer joins in MySQL so you will have to use it sooner or later. Please, again, I ask the documentation team to modify the SQL examples in the manual (especially in the tutorial section) to use the explicit JOIN forms. Humbly yours, Shawn Green Database Administrator Unimin Corporation - Spruce Pine
Re: Query returns to many results
Again, I implore all SQL coders to use the explicit JOIN syntax on all platforms that support it (Oracle being a well-known exception). It makes Oracle supports the ANSI JOIN syntax from v9 and up. Shawn Green As for the rest, I fully agree. Martijn Tonies Database Workbench - development tool for MySQL, and more! Upscene Productions http://www.upscene.com My thoughts: http://blog.upscene.com/martijn/ Database development questions? Check the forum! http://www.databasedevelopmentforum.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Query returns to many results
Now this query is run over two tables and the ab_members table contains around 302 rows. Around 1/3 of these will be where cup=kids. However, when this query is run it returns 20,700 results That's because your ... FROM ab_leader_board ablb, ab_members abm calls for a cross join--it asks for every logically possible combination of ablb and abm rows. From the rest of your query, it appears you need something like ... FROM ab_leader_board ablb INNER JOIN ab_members abm USING (name_of_joining_column) Also, do you really mean to sum all those ablb column values after having already called for all ablb column values with ablb.* ? PB - Schalk wrote: Greetings All, Please have a look at the following query: SELECT abm.mem_number, abm.first_name, abm.last_name, abm.area_represented, abm.age, abm.sex, abm.cup, ablb.*, ablb.jp + ablb.rc + ablb.fsmgp + ablb.gmc + ablb.saly + ablb.nwgp + ablb.ecgp + ablb.sams + ablb.wcc + ablb.kzngp + ablb.emc + ablb.lmgp + ablb.saff + ablb.gmgp + ablb.safy + ablb.mmw + ablb.lc + ablb.mmc + ablb.nwmc + ablb.ncc + ablb.samp + ablb.gsc + ablb.wcmgp + ablb.sapm + ablb.kznc + ablb.npc + ablb.smc + ablb.ecc + ablb.mgp + ablb.samo + ablb.cofc + ablb.cs + ablb.ncmgp + ablb.fsc + ablb.ggp + ablb.tmc + ablb.gc + ablb.yotm AS total_points FROM ab_leader_board ablb, ab_members abm WHERE abm.sex = 'Female' AND abm.cup = 'kids' ORDER BY total_points DESC Now this query is run over two tables and the ab_members table contains around 302 rows. Around 1/3 of these will be where cup=kids. However, when this query is run it returns 20,700 results :0 Any idea why this is? Also, any help or pointers as to how I can optimize this query will be much appreciated. Thank you! No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 268.0.0/267 - Release Date: 2/22/2006 -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
