Обсуждение: JDBC problem with DELETE
The following piece of code:
stmt.executeUpdate("delete from friend where name='"+someName+"'");
is returning:
SQLException: java.sql.SQLException: ERROR: Attribute 'John Doe' not
found
where someName is "John Doe".
Any ideas? The row where name='John Doe' is definitely in the table and I
can execute the statement without problems from psql.
Thanks in advance for your help.
Regards,
//Dave
Does this happen when you run the sql from psql?
How about using PreparedStatement instead of Statement? It would then handle
the quoting correctly (which is what I'm thinking is going wrong here).
Peter
--
Peter Mount
Enterprise Support
Maidstone Borough Council
Any views stated are my own, and not those of Maidstone Borough Council
-----Original Message-----
From: Dnesbitt@encryptix.com [mailto:Dnesbitt@encryptix.com]
Sent: Thursday, July 27, 2000 5:41 AM
To: pgsql-interfaces@postgresql.org
Cc: Dnesbitt@encryptix.com
Subject: [INTERFACES] JDBC problem with DELETE
The following piece of code:
stmt.executeUpdate("delete from friend where name='"+someName+"'");
is returning:
SQLException: java.sql.SQLException: ERROR: Attribute 'John Doe' not
found
where someName is "John Doe".
Any ideas? The row where name='John Doe' is definitely in the table and I
can execute the statement without problems from psql.
Thanks in advance for your help.
Regards,
//Dave
Let me answer this one... ;)
> stmt.executeUpdate("delete from friend where name='"+someName+"'");
>
> SQLException: java.sql.SQLException: ERROR: Attribute 'John Doe' not
> found
Remember that an 'Attribute' is a "field" in PG. PG is taking this as
WHERE fieldname "name" = fieldname "someName"; PG is somehow receiving
double quotes around 'someName'. I don't do java, so you figure this one
out..
Change the quoting on someName to single quotes and it should
work. Single quotes aroung strings, double quotes around field
names. Note that double quotes around field or table names are only
required if you need to preserve uppercase letters in the name.(..someone correct me if I'm not right about this...)
-Cedar
Hello! How do i change the default (ISO) date/time format to (Postgres) format? I need to 'SET DATESTYLE TO Postgres' for every session, is there a way to set this permanently? I'm using postgres 7.0.2 over linux. George Esperanza
Peter,
The sql does work from psql.
I also tried your suggestion about using PreparedStatement and that worked!
Am I doing something wrong with Statement or is it a bug?
Regards,
//Dave
> -----Original Message-----
> From: Peter Mount [mailto:petermount@it.maidstone.gov.uk]
> Sent: Wednesday, July 26, 2000 11:48 PM
> To: 'Dnesbitt@encryptix.com'; pgsql-interfaces@postgresql.org
> Subject: RE: [INTERFACES] JDBC problem with DELETE
>
>
> Does this happen when you run the sql from psql?
>
> How about using PreparedStatement instead of Statement? It
> would then handle
> the quoting correctly (which is what I'm thinking is going
> wrong here).
>
> Peter
>
> --
> Peter Mount
> Enterprise Support
> Maidstone Borough Council
> Any views stated are my own, and not those of Maidstone
> Borough Council
>
>
> -----Original Message-----
> From: Dnesbitt@encryptix.com [mailto:Dnesbitt@encryptix.com]
> Sent: Thursday, July 27, 2000 5:41 AM
> To: pgsql-interfaces@postgresql.org
> Cc: Dnesbitt@encryptix.com
> Subject: [INTERFACES] JDBC problem with DELETE
>
>
> The following piece of code:
>
> stmt.executeUpdate("delete from friend where name='"+someName+"'");
>
> is returning:
>
> SQLException: java.sql.SQLException: ERROR: Attribute
> 'John Doe' not
> found
>
> where someName is "John Doe".
>
> Any ideas? The row where name='John Doe' is definitely in
> the table and I
> can execute the statement without problems from psql.
>
> Thanks in advance for your help.
>
> Regards,
> //Dave
>
> How do i change the default (ISO) date/time format to (Postgres) format? > I need to 'SET DATESTYLE TO Postgres' for every session, is there a way > to set this permanently? http://postgresql.org/docs/postgres/x1137.htm sez: There are several ways to affect the appearance of date/time types: The PGDATESTYLE environment variable used by the backenddirectly on postmaster startup. The PGDATESTYLE environment variable used by the frontendlibpq on session startup. SET DATESTYLE SQL command. These should be sufficient. You can also adjust a #define in a header file and rebuild Postgres. Look for something with "DATESTYLE" in the include directories. - Thomas
I'm not sure, but it might be loosing the quote somewhere. The proper safe way is to use PreparedStatement. I'll try it here just to make sure it isn't a bug though. Peter -- Peter T Mount peter@retep.org.uk, peter@retepdigital.com, me@petermount.com Homepage: http://www.retep.org.uk Contact details @ http://petermount.com PostgreSQL JDBC: http://www.retep.org.uk/postgres/ Java PDF generator: http://www.retep.org.uk/pdf/ ----- Original Message ----- From: <Dnesbitt@encryptix.com> To: <petermount@it.maidstone.gov.uk>; <pgsql-interfaces@postgresql.org> Cc: <Dnesbitt@encryptix.com> Sent: Thursday, July 27, 2000 5:55 PM Subject: RE: [INTERFACES] JDBC problem with DELETE > Peter, > > The sql does work from psql. > > I also tried your suggestion about using PreparedStatement and that worked! > > Am I doing something wrong with Statement or is it a bug? > > Regards, > file://Dave > > > -----Original Message----- > > From: Peter Mount [mailto:petermount@it.maidstone.gov.uk] > > Sent: Wednesday, July 26, 2000 11:48 PM > > To: 'Dnesbitt@encryptix.com'; pgsql-interfaces@postgresql.org > > Subject: RE: [INTERFACES] JDBC problem with DELETE > > > > > > Does this happen when you run the sql from psql? > > > > How about using PreparedStatement instead of Statement? It > > would then handle > > the quoting correctly (which is what I'm thinking is going > > wrong here). > > > > Peter > > > > -- > > Peter Mount > > Enterprise Support > > Maidstone Borough Council > > Any views stated are my own, and not those of Maidstone > > Borough Council > > > > > > -----Original Message----- > > From: Dnesbitt@encryptix.com [mailto:Dnesbitt@encryptix.com] > > Sent: Thursday, July 27, 2000 5:41 AM > > To: pgsql-interfaces@postgresql.org > > Cc: Dnesbitt@encryptix.com > > Subject: [INTERFACES] JDBC problem with DELETE > > > > > > The following piece of code: > > > > stmt.executeUpdate("delete from friend where name='"+someName+"'"); > > > > is returning: > > > > SQLException: java.sql.SQLException: ERROR: Attribute > > 'John Doe' not > > found > > > > where someName is "John Doe". > > > > Any ideas? The row where name='John Doe' is definitely in > > the table and I > > can execute the statement without problems from psql. > > > > Thanks in advance for your help. > > > > Regards, > > file://Dave > >
Thanks, Peter. Please let me know if you see anything. I can't see how my Java code could be losing the single quotes. It is such a simple statement. But then again, I have made obvious coding errors that I just can't see a time or two in the past. :-) Why is PreparedStatement the proper safe way? From a coding perspective, it takes more lines of code and it would seem to also require slightly more computation as well. Regards, //Dave > -----Original Message----- > From: Peter Mount [mailto:peter@retep.org.uk] > Sent: Thursday, July 27, 2000 10:52 AM > To: Dnesbitt@encryptix.com; petermount@it.maidstone.gov.uk; > pgsql-interfaces@postgresql.org > Cc: Dnesbitt@encryptix.com > Subject: Re: [INTERFACES] JDBC problem with DELETE > > > I'm not sure, but it might be loosing the quote somewhere. > > The proper safe way is to use PreparedStatement. I'll try it > here just to > make sure it isn't a bug though. > > Peter > > -- > Peter T Mount peter@retep.org.uk, peter@retepdigital.com, > me@petermount.com > Homepage: http://www.retep.org.uk Contact details @ > http://petermount.com > PostgreSQL JDBC: http://www.retep.org.uk/postgres/ > Java PDF generator: http://www.retep.org.uk/pdf/ > > ----- Original Message ----- > From: <Dnesbitt@encryptix.com> > To: <petermount@it.maidstone.gov.uk>; > <pgsql-interfaces@postgresql.org> > Cc: <Dnesbitt@encryptix.com> > Sent: Thursday, July 27, 2000 5:55 PM > Subject: RE: [INTERFACES] JDBC problem with DELETE > > > > Peter, > > > > The sql does work from psql. > > > > I also tried your suggestion about using PreparedStatement and that > worked! > > > > Am I doing something wrong with Statement or is it a bug? > > > > Regards, > > file://Dave > > > > > -----Original Message----- > > > From: Peter Mount [mailto:petermount@it.maidstone.gov.uk] > > > Sent: Wednesday, July 26, 2000 11:48 PM > > > To: 'Dnesbitt@encryptix.com'; pgsql-interfaces@postgresql.org > > > Subject: RE: [INTERFACES] JDBC problem with DELETE > > > > > > > > > Does this happen when you run the sql from psql? > > > > > > How about using PreparedStatement instead of Statement? It > > > would then handle > > > the quoting correctly (which is what I'm thinking is going > > > wrong here). > > > > > > Peter > > > > > > -- > > > Peter Mount > > > Enterprise Support > > > Maidstone Borough Council > > > Any views stated are my own, and not those of Maidstone > > > Borough Council > > > > > > > > > -----Original Message----- > > > From: Dnesbitt@encryptix.com [mailto:Dnesbitt@encryptix.com] > > > Sent: Thursday, July 27, 2000 5:41 AM > > > To: pgsql-interfaces@postgresql.org > > > Cc: Dnesbitt@encryptix.com > > > Subject: [INTERFACES] JDBC problem with DELETE > > > > > > > > > The following piece of code: > > > > > > stmt.executeUpdate("delete from friend where > name='"+someName+"'"); > > > > > > is returning: > > > > > > SQLException: java.sql.SQLException: ERROR: Attribute > > > 'John Doe' not > > > found > > > > > > where someName is "John Doe". > > > > > > Any ideas? The row where name='John Doe' is definitely in > > > the table and I > > > can execute the statement without problems from psql. > > > > > > Thanks in advance for your help. > > > > > > Regards, > > > file://Dave > > > >
PreparedStatement is the proper way, because it allows for differences between implementations of SQL and how data types are handled. It's mainly for code that can use different database engines. ie: setString() will automatically add quotes whereas you have to do this yourself with Statement. Also, not all quotes are '. There's a method in DatabaseMetaData that returns the current quoting character (which we hard code to '). This allows some engines to use different characters. Also when you start using some of the more special types, PreparedStatement will handle them better than you could - look at setTimestamp()/getTimestamp() for an example... It's easier to keep the driver in line with the backend (the format returned changed) than to change everyone's code. Peter -- Peter Mount Enterprise Support Maidstone Borough Council Any views stated are my own, and not those of Maidstone Borough Council -----Original Message----- From: Dnesbitt@encryptix.com [mailto:Dnesbitt@encryptix.com] Sent: Saturday, July 29, 2000 3:09 AM To: peter@retep.org.uk; petermount@it.maidstone.gov.uk; pgsql-interfaces@postgresql.org Cc: Dnesbitt@encryptix.com Subject: RE: [INTERFACES] JDBC problem with DELETE Thanks, Peter. Please let me know if you see anything. I can't see how my Java code could be losing the single quotes. It is such a simple statement. But then again, I have made obvious coding errors that I just can't see a time or two in the past. :-) Why is PreparedStatement the proper safe way? From a coding perspective, it takes more lines of code and it would seem to also require slightly more computation as well. Regards, //Dave > -----Original Message----- > From: Peter Mount [mailto:peter@retep.org.uk] > Sent: Thursday, July 27, 2000 10:52 AM > To: Dnesbitt@encryptix.com; petermount@it.maidstone.gov.uk; > pgsql-interfaces@postgresql.org > Cc: Dnesbitt@encryptix.com > Subject: Re: [INTERFACES] JDBC problem with DELETE > > > I'm not sure, but it might be loosing the quote somewhere. > > The proper safe way is to use PreparedStatement. I'll try it > here just to > make sure it isn't a bug though. > > Peter > > -- > Peter T Mount peter@retep.org.uk, peter@retepdigital.com, > me@petermount.com > Homepage: http://www.retep.org.uk Contact details @ > http://petermount.com > PostgreSQL JDBC: http://www.retep.org.uk/postgres/ > Java PDF generator: http://www.retep.org.uk/pdf/ > > ----- Original Message ----- > From: <Dnesbitt@encryptix.com> > To: <petermount@it.maidstone.gov.uk>; > <pgsql-interfaces@postgresql.org> > Cc: <Dnesbitt@encryptix.com> > Sent: Thursday, July 27, 2000 5:55 PM > Subject: RE: [INTERFACES] JDBC problem with DELETE > > > > Peter, > > > > The sql does work from psql. > > > > I also tried your suggestion about using PreparedStatement and that > worked! > > > > Am I doing something wrong with Statement or is it a bug? > > > > Regards, > > file://Dave > > > > > -----Original Message----- > > > From: Peter Mount [mailto:petermount@it.maidstone.gov.uk] > > > Sent: Wednesday, July 26, 2000 11:48 PM > > > To: 'Dnesbitt@encryptix.com'; pgsql-interfaces@postgresql.org > > > Subject: RE: [INTERFACES] JDBC problem with DELETE > > > > > > > > > Does this happen when you run the sql from psql? > > > > > > How about using PreparedStatement instead of Statement? It > > > would then handle > > > the quoting correctly (which is what I'm thinking is going > > > wrong here). > > > > > > Peter > > > > > > -- > > > Peter Mount > > > Enterprise Support > > > Maidstone Borough Council > > > Any views stated are my own, and not those of Maidstone > > > Borough Council > > > > > > > > > -----Original Message----- > > > From: Dnesbitt@encryptix.com [mailto:Dnesbitt@encryptix.com] > > > Sent: Thursday, July 27, 2000 5:41 AM > > > To: pgsql-interfaces@postgresql.org > > > Cc: Dnesbitt@encryptix.com > > > Subject: [INTERFACES] JDBC problem with DELETE > > > > > > > > > The following piece of code: > > > > > > stmt.executeUpdate("delete from friend where > name='"+someName+"'"); > > > > > > is returning: > > > > > > SQLException: java.sql.SQLException: ERROR: Attribute > > > 'John Doe' not > > > found > > > > > > where someName is "John Doe". > > > > > > Any ideas? The row where name='John Doe' is definitely in > > > the table and I > > > can execute the statement without problems from psql. > > > > > > Thanks in advance for your help. > > > > > > Regards, > > > file://Dave > > > >
Dave, Um... just thought I'd ask... Are you really using "John Doe" (as in the email) or is that just a dummy placeholder for the real names you inserted? The reason why I ask is that I remember the first time I was bit by the ole single quote problem was dealing with an 'O'Connor' that, of course, really should have been an 'O''Connor'. Thought maybe something similar was happening here... -Tim. -----Original Message----- From: Dnesbitt@encryptix.com [mailto:Dnesbitt@encryptix.com] Sent: Friday, July 28, 2000 10:09 PM To: peter@retep.org.uk; petermount@it.maidstone.gov.uk; pgsql-interfaces@postgresql.org Cc: Dnesbitt@encryptix.com Subject: RE: [INTERFACES] JDBC problem with DELETE Thanks, Peter. Please let me know if you see anything. I can't see how my Java code could be losing the single quotes. It is such a simple statement. But then again, I have made obvious coding errors that I just can't see a time or two in the past. :-) Why is PreparedStatement the proper safe way? From a coding perspective, it takes more lines of code and it would seem to also require slightly more computation as well. Regards, //Dave > -----Original Message----- > From: Peter Mount [mailto:peter@retep.org.uk] > Sent: Thursday, July 27, 2000 10:52 AM > To: Dnesbitt@encryptix.com; petermount@it.maidstone.gov.uk; > pgsql-interfaces@postgresql.org > Cc: Dnesbitt@encryptix.com > Subject: Re: [INTERFACES] JDBC problem with DELETE > > > I'm not sure, but it might be loosing the quote somewhere. > > The proper safe way is to use PreparedStatement. I'll try it > here just to > make sure it isn't a bug though. > > Peter > > -- > Peter T Mount peter@retep.org.uk, peter@retepdigital.com, > me@petermount.com > Homepage: http://www.retep.org.uk Contact details @ > http://petermount.com > PostgreSQL JDBC: http://www.retep.org.uk/postgres/ > Java PDF generator: http://www.retep.org.uk/pdf/ > > ----- Original Message ----- > From: <Dnesbitt@encryptix.com> > To: <petermount@it.maidstone.gov.uk>; > <pgsql-interfaces@postgresql.org> > Cc: <Dnesbitt@encryptix.com> > Sent: Thursday, July 27, 2000 5:55 PM > Subject: RE: [INTERFACES] JDBC problem with DELETE > > > > Peter, > > > > The sql does work from psql. > > > > I also tried your suggestion about using PreparedStatement and that > worked! > > > > Am I doing something wrong with Statement or is it a bug? > > > > Regards, > > file://Dave > > > > > -----Original Message----- > > > From: Peter Mount [mailto:petermount@it.maidstone.gov.uk] > > > Sent: Wednesday, July 26, 2000 11:48 PM > > > To: 'Dnesbitt@encryptix.com'; pgsql-interfaces@postgresql.org > > > Subject: RE: [INTERFACES] JDBC problem with DELETE > > > > > > > > > Does this happen when you run the sql from psql? > > > > > > How about using PreparedStatement instead of Statement? It > > > would then handle > > > the quoting correctly (which is what I'm thinking is going > > > wrong here). > > > > > > Peter > > > > > > -- > > > Peter Mount > > > Enterprise Support > > > Maidstone Borough Council > > > Any views stated are my own, and not those of Maidstone > > > Borough Council > > > > > > > > > -----Original Message----- > > > From: Dnesbitt@encryptix.com [mailto:Dnesbitt@encryptix.com] > > > Sent: Thursday, July 27, 2000 5:41 AM > > > To: pgsql-interfaces@postgresql.org > > > Cc: Dnesbitt@encryptix.com > > > Subject: [INTERFACES] JDBC problem with DELETE > > > > > > > > > The following piece of code: > > > > > > stmt.executeUpdate("delete from friend where > name='"+someName+"'"); > > > > > > is returning: > > > > > > SQLException: java.sql.SQLException: ERROR: Attribute > > > 'John Doe' not > > > found > > > > > > where someName is "John Doe". > > > > > > Any ideas? The row where name='John Doe' is definitely in > > > the table and I > > > can execute the statement without problems from psql. > > > > > > Thanks in advance for your help. > > > > > > Regards, > > > file://Dave > > > >
Tim, It is not really "John Doe", but it also does not have any embedded single quotes. It does, however, have an embedded space character. I don't know if this has anything to do with it, but it is the only thing I can think of that is different than line 380 in Peter's example file ImageViewer.java. Regards, //Dave > -----Original Message----- > From: Dwelle, Timothy [mailto:TDwelle@xperts.com] > Sent: Monday, July 31, 2000 9:13 AM > To: 'Dnesbitt@encryptix.com'; peter@retep.org.uk; > petermount@it.maidstone.gov.uk; pgsql-interfaces@postgresql.org > Subject: RE: [INTERFACES] JDBC problem with DELETE > > > Dave, > > Um... just thought I'd ask... > > Are you really using "John Doe" (as in the email) > or is that just a dummy placeholder for the real > names you inserted? > > The reason why I ask is that I remember the first > time I was bit by the ole single quote problem was > dealing with an 'O'Connor' that, of course, really > should have been an 'O''Connor'. Thought maybe > something similar was happening here... > > -Tim. > > > -----Original Message----- > From: Dnesbitt@encryptix.com [mailto:Dnesbitt@encryptix.com] > Sent: Friday, July 28, 2000 10:09 PM > To: peter@retep.org.uk; petermount@it.maidstone.gov.uk; > pgsql-interfaces@postgresql.org > Cc: Dnesbitt@encryptix.com > Subject: RE: [INTERFACES] JDBC problem with DELETE > > > Thanks, Peter. Please let me know if you see anything. > > I can't see how my Java code could be losing the single > quotes. It is such > a simple statement. But then again, I have made obvious > coding errors that > I just can't see a time or two in the past. :-) > > Why is PreparedStatement the proper safe way? From a coding > perspective, it > takes more lines of code and it would seem to also require > slightly more > computation as well. > > Regards, > //Dave > > > -----Original Message----- > > From: Peter Mount [mailto:peter@retep.org.uk] > > Sent: Thursday, July 27, 2000 10:52 AM > > To: Dnesbitt@encryptix.com; petermount@it.maidstone.gov.uk; > > pgsql-interfaces@postgresql.org > > Cc: Dnesbitt@encryptix.com > > Subject: Re: [INTERFACES] JDBC problem with DELETE > > > > > > I'm not sure, but it might be loosing the quote somewhere. > > > > The proper safe way is to use PreparedStatement. I'll try it > > here just to > > make sure it isn't a bug though. > > > > Peter > > > > -- > > Peter T Mount peter@retep.org.uk, peter@retepdigital.com, > > me@petermount.com > > Homepage: http://www.retep.org.uk Contact details @ > > http://petermount.com > > PostgreSQL JDBC: http://www.retep.org.uk/postgres/ > > Java PDF generator: http://www.retep.org.uk/pdf/ > > > > ----- Original Message ----- > > From: <Dnesbitt@encryptix.com> > > To: <petermount@it.maidstone.gov.uk>; > > <pgsql-interfaces@postgresql.org> > > Cc: <Dnesbitt@encryptix.com> > > Sent: Thursday, July 27, 2000 5:55 PM > > Subject: RE: [INTERFACES] JDBC problem with DELETE > > > > > > > Peter, > > > > > > The sql does work from psql. > > > > > > I also tried your suggestion about using > PreparedStatement and that > > worked! > > > > > > Am I doing something wrong with Statement or is it a bug? > > > > > > Regards, > > > file://Dave > > > > > > > -----Original Message----- > > > > From: Peter Mount [mailto:petermount@it.maidstone.gov.uk] > > > > Sent: Wednesday, July 26, 2000 11:48 PM > > > > To: 'Dnesbitt@encryptix.com'; pgsql-interfaces@postgresql.org > > > > Subject: RE: [INTERFACES] JDBC problem with DELETE > > > > > > > > > > > > Does this happen when you run the sql from psql? > > > > > > > > How about using PreparedStatement instead of Statement? It > > > > would then handle > > > > the quoting correctly (which is what I'm thinking is going > > > > wrong here). > > > > > > > > Peter > > > > > > > > -- > > > > Peter Mount > > > > Enterprise Support > > > > Maidstone Borough Council > > > > Any views stated are my own, and not those of Maidstone > > > > Borough Council > > > > > > > > > > > > -----Original Message----- > > > > From: Dnesbitt@encryptix.com [mailto:Dnesbitt@encryptix.com] > > > > Sent: Thursday, July 27, 2000 5:41 AM > > > > To: pgsql-interfaces@postgresql.org > > > > Cc: Dnesbitt@encryptix.com > > > > Subject: [INTERFACES] JDBC problem with DELETE > > > > > > > > > > > > The following piece of code: > > > > > > > > stmt.executeUpdate("delete from friend where > > name='"+someName+"'"); > > > > > > > > is returning: > > > > > > > > SQLException: java.sql.SQLException: ERROR: Attribute > > > > 'John Doe' not > > > > found > > > > > > > > where someName is "John Doe". > > > > > > > > Any ideas? The row where name='John Doe' is definitely in > > > > the table and I > > > > can execute the statement without problems from psql. > > > > > > > > Thanks in advance for your help. > > > > > > > > Regards, > > > > file://Dave > > > > > > >