# Mrelation does not exist **URL:** \ **Category:** Ruby\ **Created:** [September 8, 2006, 5:06pm UTC](https://www.ruby-forum.com/t/mrelation-does-not-exist/68024 "2006-09-08T17:06:36Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![aladrin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/5f8ce5/32.png) [@aladrin](https://www.ruby-forum.com/u/aladrin)\ **Post date:** [September 8, 2006, 5:06pm UTC](https://www.ruby-forum.com/t/mrelation-does-not-exist/68024/1 "2006-09-08T17:06:36Z")
Okay I originally posted the following in the rails forum, which was the wrong place to post it as I’m not using Rails (that thread just happens to be what came up in Google). Perhaps one of you could help me C:\Documents and Settings\Will\My Documents\src\mm\web\cgi-bin\>processBounces.rb Connection Test Successful - Connected To The Database Parsing Logfile Finished Processing Bounces… select id, bounce from sql\_languages where email=‘removed\_email\_address@domain.invalid’; c:/ruby/lib/ruby/site\_ruby/1.8/DBD/Pg/Pg.rb:640:in `execute': ERROR C42P01 Mrelation "sql_languages" does not exist Fnamespace.c L201 RRangeVa rGetRelid (DBI::ProgrammingError) from c:/ruby/lib/ruby/site_ruby/1.8/dbi.rb:617:in`execute’ from C:/Documents and Settings/Will/My Documents/src/mm/web/cgi-bin/proc essBounces.rb:84:in `updateBounceCount' from C:/Documents and Settings/Will/My Documents/src/mm/web/cgi-bin/proc essBounces.rb:79:in`updateBounceCount’ from C:/Documents and Settings/Will/My Documents/src/mm/web/cgi-bin/proc essBounces.rb:144 from C:/Documents and Settings/Will/My Documents/src/mm/web/cgi-bin/proc essBounces.rb:142 Roughly the same issue, but it doesn’t seem to be an issue with the serial… any ideas? The code is as follows: data\_sources.each do |table\_name| email\_address = email\_address.downcase selectQry = “select id, bounce from “+table\_name+” where email=’”+email\_address+"’;" sth = dbh.prepare(selectQry) sth.execute while rows = sth.fetch do printf rows[0], rows[1],"\n" end end ---
**Author:** ![aladrin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/5f8ce5/32.png) [@aladrin](https://www.ruby-forum.com/u/aladrin)\ **Post date:** [September 8, 2006, 7:06pm UTC](https://www.ruby-forum.com/t/mrelation-does-not-exist/68024/2 "2006-09-08T19:06:28Z")
I should also note that it’s a Postgres-based database that I’m connecting to. I’ve scoured the internet, but everything has lead to dead ends. William C. wrote: \src\mm\web\cgi-bin\>processBounces.rb > Connection Test Successful - Connected To The Database > Parsing Logfile Finished > Processing Bounces… > select id, bounce from sql\_languages where > email=‘removed\_email\_address@domain.invalid’; > c:/ruby/lib/ruby/site\_ruby/1.8/DBD/Pg/Pg.rb:640:in `execute': ERROR C42P01 Mrelation "sql_languages" does not exist Fnamespace.c L201 RRangeVa rGetRelid (DBI::ProgrammingError) from c:/ruby/lib/ruby/site_ruby/1.8/dbi.rb:617:in`execute’ > from C:/Documents and Settings/Will/My > Documents/src/mm/web/cgi-bin/proc > essBounces.rb:84:in `updateBounceCount' from C:/Documents and Settings/Will/My Documents/src/mm/web/cgi-bin/proc essBounces.rb:79:in`updateBounceCount’ > from C:/Documents and Settings/Will/My > Documents/src/mm/web/cgi-bin/proc > essBounces.rb:144 > from C:/Documents and Settings/Will/My > Documents/src/mm/web/cgi-bin/proc > essBounces.rb:142 ---
**Author:** ![aladrin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/5f8ce5/32.png) [@aladrin](https://www.ruby-forum.com/u/aladrin)\ **Post date:** [September 8, 2006, 7:49pm UTC](https://www.ruby-forum.com/t/mrelation-does-not-exist/68024/3 "2006-09-08T19:49:30Z")
William C. wrote: > select id, bounce from sql\_languages where > email=‘removed\_email\_address@domain.invalid’; > c:/ruby/lib/ruby/site\_ruby/1.8/DBD/Pg/Pg.rb:640:in `execute’: ERROR > C42P01 > Mrelation “sql\_languages” does not exist Fnamespace.c L201 > RRangeVa And of course, the table ‘sql\_languages’ DOES exist, right? ---
**Author:** ![aladrin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/5f8ce5/32.png) [@aladrin](https://www.ruby-forum.com/u/aladrin)\ **Post date:** [September 8, 2006, 8:58pm UTC](https://www.ruby-forum.com/t/mrelation-does-not-exist/68024/4 "2006-09-08T20:58:36Z")
William C. wrote: > William C. wrote: > > > select id, bounce from sql\_languages where > > email=‘removed\_email\_address@domain.invalid’; > > c:/ruby/lib/ruby/site\_ruby/1.8/DBD/Pg/Pg.rb:640:in `execute’: ERROR > > C42P01 > > Mrelation “sql\_languages” does not exist Fnamespace.c L201 > > RRangeVa > > And of course, the table ‘sql\_languages’ DOES exist, right? Yes, the table ‘sql\_languages’ does exist. You don’t have to try to be a smart allack about it. I’m teaching myself this language and just wanted some help. It’s Postgres. If you aren’t familiar with it, each database contains various schemas. sql\_languages is in the “information\_schema” schema. ---
**Author:** ![aladrin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/5f8ce5/32.png) [@aladrin](https://www.ruby-forum.com/u/aladrin)\ **Post date:** [September 8, 2006, 9:21pm UTC](https://www.ruby-forum.com/t/mrelation-does-not-exist/68024/5 "2006-09-08T21:21:25Z")
William C. wrote: > William C. wrote: > > > William C. wrote: > > > > > William C. wrote: > > > > > > > select id, bounce from sql\_languages where > > > > email=‘removed\_email\_address@domain.invalid’; > > > > c:/ruby/lib/ruby/site\_ruby/1.8/DBD/Pg/Pg.rb:640:in `execute’: ERROR > > > > C42P01 > > > > Mrelation “sql\_languages” does not exist Fnamespace.c L201 > > > > RRangeVa > > > > > > And of course, the table ‘sql\_languages’ DOES exist, right? > > > > Yes, the table ‘sql\_languages’ does exist. You don’t have to try to be > > a smart allack about it. I’m teaching myself this language and just > > wanted some help. > > > > It’s Postgres. If you aren’t familiar with it, each database contains > > various schemas. sql\_languages is in the “information\_schema” schema. > > I’m not being a smart aleck about it. You’d be amazed how often it’s > something simple that was just overlooked. Oh, okay. Sorry about that, i misjudged your tone! But yeah, essentially I am using Ruby’s DBI module as such (simplified)… dbh = DBI.connect(“DBI:Pg:mavmail:192.168.1.19”, “mavmail”, “”) data\_sources = dbh.tables …the above should return an array of table names, which it indeed does. It’s including the table names for not only the public tables, but the ones stored in the information schema as well. Then I do the following: data\_sources.each{ do |table\_name| sth = dbh.prepare("SELECT something from "+table\_name) sth.execute end …and then outputs the error noted above. I believe it’s crapping out because it’s running the query against non-public tables, so it can’t ‘see’ them. Some weird quirk with Postgres as far as I can tell. If I could return only the public tables then it’d make my life easier… it’s back to the drawing board I guess. ---
**Author:** ![aladrin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/5f8ce5/32.png) [@aladrin](https://www.ruby-forum.com/u/aladrin)\ **Post date:** [September 8, 2006, 10:32pm UTC](https://www.ruby-forum.com/t/mrelation-does-not-exist/68024/6 "2006-09-08T22:32:29Z")
William C. wrote: > dbh = DBI.connect(“DBI:Pg:mavmail:192.168.1.19”, “mavmail”, “”) > data\_sources = dbh.tables > > …the above should return an array of table names, which it indeed > does. It’s including the table names for not only the public tables, > but the ones stored in the information schema as well. Then I do the > following: > > data\_sources.each{ do |table\_name| > sth = dbh.prepare("SELECT something from "+table\_name) > sth.execute > end > > …and then outputs the error noted above. I believe it’s crapping out > because it’s running the query against non-public tables, so it can’t > ‘see’ them. Some weird quirk with Postgres as far as I can tell. If I > could return only the public tables then it’d make my life easier… > it’s back to the drawing board I guess. Hm, yeah, that’s not very helpful. It doesn’t seem to provide a way to tell what schema it’s in or anything. If you could, you could simply do schema.table\_name and it would pull it like you want. It looks like it just pulls the list of tables by doing: select tablename from pg\_catalog.pg\_tables; If you pulled the information yourself, you could choose only the schema ‘public’ and get what you want. ---
**Author:** ![aladrin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/5f8ce5/32.png) [@aladrin](https://www.ruby-forum.com/u/aladrin)\ **Post date:** [September 8, 2006, 9:06pm UTC](https://www.ruby-forum.com/t/mrelation-does-not-exist/68024/7 "2006-09-08T21:06:16Z")
William C. wrote: > William C. wrote: > > > William C. wrote: > > > > > select id, bounce from sql\_languages where > > > email=‘removed\_email\_address@domain.invalid’; > > > c:/ruby/lib/ruby/site\_ruby/1.8/DBD/Pg/Pg.rb:640:in `execute’: ERROR > > > C42P01 > > > Mrelation “sql\_languages” does not exist Fnamespace.c L201 > > > RRangeVa > > > > And of course, the table ‘sql\_languages’ DOES exist, right? > > Yes, the table ‘sql\_languages’ does exist. You don’t have to try to be > a smart allack about it. I’m teaching myself this language and just > wanted some help. > > It’s Postgres. If you aren’t familiar with it, each database contains > various schemas. sql\_languages is in the “information\_schema” schema. I’m not being a smart aleck about it. You’d be amazed how often it’s something simple that was just overlooked.