[Mono-list] Npgsql error

[Fabian Salamanca Dominguez]

Thanks to all!!

The last one prints:

System.String System.Int32

never prints null, I'll try the other suggestions...

java-ish lol, what's java?

On 8/5/05, Francisco Figueiredo Jr. <fxjrlists at yahoo.com.br> wrote:
> 
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> Fabian Salamanca Dominguez wrote:
> >
> > Hi
> >
> 
> Hi Fabian!
> 
> > I tried to compile a simple C# program and access a Postgresql DB but I
> > got this error in runtime (it compiled with no errors) :
> >
> > [fsalaman at ipdserver Mono]$ mcs dbaccess.cs -r:Npgsql.dll -r:
> System.Data.dll
> > [fsalaman at ipdserver Mono]$ mono dbaccess.exe
> >
> > Unhandled Exception: System.InvalidCastException: Cannot cast from
> > source type to destination type.
> > in <0x000e1> dbAccess:Main (System.String[] args)
> 
> 
> > string sql =
> > "SELECT operatingsystem, nodeid " +
> > "FROM assets";
> 
> 
> What are the sql types of operatingsystem and nodeid?
> Npgsql doesn't do any implicit conversion of types.
> 
> > dbcmd.CommandText = sql;
> > IDataReader reader = dbcmd.ExecuteReader();
> > while(reader.Read()) {
> > string operatingsystem = (string) reader["operatingsystem"];
> > string nodeid = (string) reader["nodeid"];
> > Console.WriteLine("OS: " +
> > operatingsystem + " " + nodeid);
> > }
> 
> 
> To be sure, do the following:
> 
> Console.WriteLine(reader["operatingsystem"].GetType());
> 
> This will show you what type is being returned.
> 
> I hope it helps.
> 
> 
> 
> - --
> Regards,
> 
> Francisco Figueiredo Jr.
> Npgsql Lead Developer
> http://gborg.postgresql.org/project/npgsql
> MonoBrasil Project Founder Member
> http://monobrasil.softwarelivre.org
> 
> 
> - -------------
> "Science without religion is lame;
> religion without science is blind."
> 
> ~ Albert Einstein
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> 
> 
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-- 
Fabian
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