Hello, I''m wondering if someone might be able to offer me a solution to the following problem that has so far stumped me. I''m trying to get the distinct months (and years) from a date field to display as a list in a view. For example, there might be a number of records stored with dates in the table ''headlines'': name date record1 21-09-2008 record2 15-09-2008 record3 03-08-2008 record4 02-08-2008 record5 12-07-2008 etc. From which I''d like to get all distinct years and months to display in a view something like what might be seen under the ''Archives'' section of a blog page, like this: September 2008 August 2008 July 2008 etc. I have tried to set the following sql statement in my controller to find the months using find_by_sql: @headlines_month = Headline.find_by_sql("SELECT distinct MONTHNAME(date) FROM headlines") However, this errors out as: PGError: ERROR: function monthname(date) does not exist at character 17 HINT: No function matches the given name and argument types. You may need to add explicit type casts. : SELECT distinct MONTHNAME(date) FROM headlines It''s monthname() which is what''s causing it to error out as, if i remove monthname() there are no problems. I''m not sure if this is a problem of my limited understanding of that rails command or an error with my sql statement but I''m out of ideas so if anyone might have an idea for an effective solution - or can point me in the right direction - I''d very much appreciate it. Thanks in advance. Best IRT --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Hi, it looks like your Postgresql doesn''t support the function monthname(). Try this statement on a Postgresql-console. Which Version of Postgresql do you have installed? Greetings Johannes Am Dienstag, den 23.09.2008, 10:43 -0700 schrieb it:> Hello, > I''m wondering if someone might be able to offer me a solution to the > following problem that has so far stumped me. > I''m trying to get the distinct months (and years) from a date field to > display as a list in a view. For example, there might be a number of > records stored with dates in the table ''headlines'': > name date > record1 21-09-2008 > record2 15-09-2008 > record3 03-08-2008 > record4 02-08-2008 > record5 12-07-2008 > etc. > > From which I''d like to get all distinct years and months to display in > a view something like what might be seen under the ''Archives'' section > of a blog page, like this: > September 2008 > August 2008 > July 2008 > etc. > > I have tried to set the following sql statement in my controller to > find the months using find_by_sql: > @headlines_month = Headline.find_by_sql("SELECT distinct > MONTHNAME(date) FROM headlines") > > However, this errors out as: > > PGError: ERROR: function monthname(date) does not exist at character > 17 > HINT: No function matches the given name and argument types. You may > need to add explicit type casts. > : SELECT distinct MONTHNAME(date) FROM headlines > > It''s monthname() which is what''s causing it to error out as, if i > remove monthname() there are no problems. > I''m not sure if this is a problem of my limited understanding of that > rails command or an error with my sql statement but I''m out of ideas > so if anyone might have an idea for an effective solution - or can > point me in the right direction - I''d very much appreciate it. > > Thanks in advance. > Best > IRT > > > >--~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Thanks for the reply Johannes. I think you''re right about Postgresql not supporting monthname(). I managed to get round this using the following: @headlines_month = Headline.find_by_sql("SELECT DISTINCT DATE_PART(''year'', date) as year, DATE_PART(''month'', date) as month FROM headlines ORDER BY year DESC") I appreciate your taking time to reply. Best regards IRT On 23 Sep, 19:46, "Johannes J. Schmidt" <d...-xIc/GT63x2dWk0Htik3J/w@public.gmane.org> wrote:> Hi, > > it looks like your Postgresql doesn''t support the function monthname(). > Try this statement on a Postgresql-console. > Which Version of Postgresql do you have installed? > > Greetings > Johannes > > Am Dienstag, den 23.09.2008, 10:43 -0700 schrieb it: > > > Hello, > > I''m wondering if someone might be able to offer me a solution to the > > following problem that has so far stumped me. > > I''m trying to get the distinct months (and years) from a date field to > > display as a list in a view. For example, there might be a number of > > records stored with dates in the table ''headlines'': > > name date > > record1 21-09-2008 > > record2 15-09-2008 > > record3 03-08-2008 > > record4 02-08-2008 > > record5 12-07-2008 > > etc. > > > From which I''d like to get all distinct years and months to display in > > a view something like what might be seen under the ''Archives'' section > > of a blog page, like this: > > September 2008 > > August 2008 > > July 2008 > > etc. > > > I have tried to set the following sql statement in my controller to > > find the months using find_by_sql: > > @headlines_month = Headline.find_by_sql("SELECT distinct > > MONTHNAME(date) FROM headlines") > > > However, this errors out as: > > > PGError: ERROR: function monthname(date) does not exist at character > > 17 > > HINT: No function matches the given name and argument types. You may > > need to add explicit type casts. > > : SELECT distinct MONTHNAME(date) FROM headlines > > > It''s monthname() which is what''s causing it to error out as, if i > > remove monthname() there are no problems. > > I''m not sure if this is a problem of my limited understanding of that > > rails command or an error with my sql statement but I''m out of ideas > > so if anyone might have an idea for an effective solution - or can > > point me in the right direction - I''d very much appreciate it. > > > Thanks in advance. > > Best > > IRT--~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
To display the month name you could either: 1. Create a function that would return the month name based on the month numeric value and call it from your SQL statement. This would allow you to use the same functionality in more than 1 statement, or... 2. Use a case clause. Not sure how the syntax would be in Postgresql. Something like this: case when DATE_PART(''month'', date) = 1 then ''January'' when DATE_PART(''month'', date) = 2 then ''February'' ......... end Pepe On Sep 23, 3:45 pm, it <envnew...-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:> Thanks for the reply Johannes. I think you''re right about Postgresql > not supporting monthname(). > > I managed to get round this using the following: > @headlines_month = Headline.find_by_sql("SELECT DISTINCT > DATE_PART(''year'', date) as year, DATE_PART(''month'', date) as month > FROM headlines ORDER BY year DESC") > > I appreciate your taking time to reply. > Best regards > IRT > > On 23 Sep, 19:46, "Johannes J. Schmidt" <d...-xIc/GT63x2dWk0Htik3J/w@public.gmane.org> wrote: > > > Hi, > > > it looks like your Postgresql doesn''t support the function monthname(). > > Try this statement on a Postgresql-console. > > Which Version of Postgresql do you have installed? > > > Greetings > > Johannes > > > Am Dienstag, den 23.09.2008, 10:43 -0700 schrieb it: > > > > Hello, > > > I''m wondering if someone might be able to offer me a solution to the > > > following problem that has so far stumped me. > > > I''m trying to get the distinct months (and years) from a date field to > > > display as a list in a view. For example, there might be a number of > > > records stored with dates in the table ''headlines'': > > > name date > > > record1 21-09-2008 > > > record2 15-09-2008 > > > record3 03-08-2008 > > > record4 02-08-2008 > > > record5 12-07-2008 > > > etc. > > > > From which I''d like to get all distinct years and months to display in > > > a view something like what might be seen under the ''Archives'' section > > > of a blog page, like this: > > > September 2008 > > > August 2008 > > > July 2008 > > > etc. > > > > I have tried to set the following sql statement in my controller to > > > find the months using find_by_sql: > > > @headlines_month = Headline.find_by_sql("SELECT distinct > > > MONTHNAME(date) FROM headlines") > > > > However, this errors out as: > > > > PGError: ERROR: function monthname(date) does not exist at character > > > 17 > > > HINT: No function matches the given name and argument types. You may > > > need to add explicit type casts. > > > : SELECT distinct MONTHNAME(date) FROM headlines > > > > It''s monthname() which is what''s causing it to error out as, if i > > > remove monthname() there are no problems. > > > I''m not sure if this is a problem of my limited understanding of that > > > rails command or an error with my sql statement but I''m out of ideas > > > so if anyone might have an idea for an effective solution - or can > > > point me in the right direction - I''d very much appreciate it. > > > > Thanks in advance. > > > Best > > > IRT--~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe@googlegroups.com For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---