Re: [Firebird-net-provider] Convert BLOB to string

[Martin <mc...@we...>]

Hi,

I am using .net provider 1.5 RC2.
I am using vb.net code. The line that is throwing the exception is

strDesciption = CType(objCMD.ExecuteScalar(), String)

and the exception description is

Cast from type 'Byte()' to type 'String' is not valid.

I have checked that a record is being broght back. Perhaps I have the cast
syntax wrong...

The full code that I am using is below. If I comment the cat out and just
use

objCMD.ExecuteScalar()

then all works fine.

I am executing a stored procedure. and the full code that I am using is
below for reference.


cheers

martin.



Try
            Dim objConn As FirebirdSql.Data.Firebird.FbConnection = New
FirebirdSql.Data.Firebird.FbConnection
            Dim objCMD As FirebirdSql.Data.Firebird.FbCommand = New
FirebirdSql.Data.Firebird.FbCommand
            Dim objTran As FirebirdSql.Data.Firebird.FbTransaction
            objConn.ConnectionString =
System.Configuration.ConfigurationSettings.AppSettings("DbConnectionString")
            objConn.Open()
            objCMD.Connection = objConn
            objTran = objConn.BeginTransaction()
            objCMD.Transaction = objTran
            objCMD.CommandText = "SP_EE_GET_GROUP_DESCRIPTION"
            objCMD.CommandType = CommandType.StoredProcedure
            Dim P1 As New FirebirdSql.Data.Firebird.FbParameter
            P1.Direction = ParameterDirection.Input
            P1 = objCMD.Parameters.Add("@ID", 87)
            Dim strDesciption As String 'Variable to hold the description
string that will be returned

            strDesciption = CType(objCMD.ExecuteScalar(), String)
<<<<<<<<<<<<<<<<<<<<---------  THROWS EXCEPTION


            objCMD.Dispose()
            objTran.Commit()
            objTran.Dispose()
            objConn.Close()
        Catch ex As Exception
            Trace.Write(ex.Message())
        End Try






"Carlos Guzmán Álvarez" <car...@te...> wrote in message
news:400...@te......
> Hello:
>
> > BLOB SUB_TYPE 1 SEGMENT SIZE 80 CHARACTER SET NONE
>
> It's correct, which version of the .NET Data Provider are you using ??
>
> I have tested this with 1.5, and runs fine:
>
> FbConnection connection = new FbConnection(connectionString);
> connection.Open();
>
> string sql = "select clob_field from test where int_field = 1";
>
> FbCommand command = new FbCommand(sql, connection);
>
> string value = (string)command.ExecuteScalar();
>
> connection.Close();
>
>
>
>
> --
> Best regards
>
> Carlos Guzmán Álvarez
> Vigo-Spain
>
>
>
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