错误SQL30061N使用IBM.EntityFrameworkCore从Visual Studio 2017 c＃中的DB2 iSeries提取数据

Question

I'm looking to pull data from a DB2 File/Table that resides on a IBM iSeries using IBM.EntityFrameworkCore This has been a difficult task and it seems like I have ran into problems all along the way. Most of them I have been able to work through by reading comments on this site, however, I cannot find anything to help me with this one.

I have performed the following steps:

1. Created a new Console App Project for .Net Core
2. Installed IBM.EntityFrameworkCore version 1.1.1.101
3. Updated my PATH environment variable so that it points to C:\\Users\\MyUserName.nuget\\packages\\ibm.data.db2.core\\1.1.1.101\\build\\clidriver\\bin
4. Checked to make sure the correct driver was installed and being loaded by using the db2level command from the command prompt.
5. Within the Console App Project I have created three classes named iSeriesContext.cs, SYSVARIABLES.cs, and Program.cs.

For testing purposes I'm using a system Schema/Database that I believe ships standard with DB2 on the iSeries.

The Program.cs contains:

using System.Linq;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            iSeriesContext context = new iSeriesContext();
            var results = context.SYSVARIABLES.Where(p => p.VARIABLE_NAME == "test").FirstOrDefault();
        }
    //enter code here
    }
}

The iSeriesContext.cs contains:

using System;
using Microsoft.EntityFrameworkCore;
using System.Linq;
using IBM.EntityFrameworkCore;
using IBM.EntityFrameworkCore.Storage.Internal;

namespace ConsoleApp1
{
    public class iSeriesContext : DbContext
    {
        public iSeriesContext() : base() { }
        public DbSet<SYSVARIABLE> SYSVARIABLES { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseDb2(@"server=192.0.0.1:446; Database=QSYS2; userid=username; password=password", p => p.SetServerInfo(IBMDBServerType.AS400, IBMDBServerVersion.AS400_07_01));
        }
    }
}

The SYSVARIABLE.cs contains:

using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    public class SYSVARIABLE
    {
        [Key]
        public string VARIABLE_SCHEMA { get; set; }
        public string VARIABLE_NAME { get; set; }
        public string SYSTEM_VAR_SCHEMA { get; set; }
    }
}

Additional Notes:

I have conformed that my iSeries OS is V7R1.

I have confirmed that my drda service on the iSeries is listening on port 446 and when I run my code I do see the "last activity date/time" update to the current time.

The solution compiles with no errors. However, when I run it I get a

"IBM.Data.DB2.Core.DB2Exception: 'External component has thrown an exception.'" error on this line "var results = context.SYSVARIABLES.Where(p => p.VARIABLE_NAME == "test").FirstOrDefault();" in Program.cs

The details of the error are:

IBM.Data.DB2.Core.DB2Exception occurred
  HResult=0x80004005
  Message=ERROR [08004] [IBM] SQL30061N  The database alias or database name 

"QSYS2             " was not found at the remote node.  SQLSTATE=08004
    [IBM] SQL30061N  The database alias or database name "QSYS2             " was not found at the remote node.  SQLSTATE=08004

  Source=<Cannot evaluate the exception source>
  StackTrace:
   at IBM.Data.DB2.Core.DB2ConnPool.Open(DB2Connection connection, String& szConnectionString, DB2ConnSettings& ppSettings, Object& ppConn)
   at IBM.Data.DB2.Core.DB2Connection.Open()
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.Open()
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryingEnumerable.Enumerator.BufferlessMoveNext(Boolean buffer)
   at Microsoft.EntityFrameworkCore.Query.QueryMethodProvider.<_ShapedQuery>d__3`1.MoveNext()
   at System.Linq.Enumerable.TryGetFirst[TSource](IEnumerable`1 source, Boolean& found)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass20_0`1.<CompileQueryCore>b__0(QueryContext qc)
   at System.Linq.Queryable.FirstOrDefault[TSource](IQueryable`1 source)
   at ConsoleApp1.Program.Main(String[] args) in C:\Users\username\source\repos\IBMEntityFrameworkTest\ConsoleApp1\Program.cs:line 10
"

I feel like I'm very close. Any help would be appreciated.

Answer 1

Can you try using ODBC to make a connection to this data source? When you do that, you get a dialog which lets you choose the Package Library and the Library List. The message indicates that QSYS2 is not found. So that may not be the right name for the Package. In the screenshot below the package name is "QGPL".

Once you've got the ODBC datasource configured, test it using a very simple C# app that uses System.Data.Odbc.OdbcConnection with our connection string which simply uses that DSN. That way you get around any EF nonsense and can verify whether you can actually read the data you're looking for. Once you've proven you can use the DSN and connection string to read your table, then you can see if that leads to new parameters to use with EF.

Note that you could also just use plain old ODBC to read your data. This is what we do. Then, once the DSN is set up we don't have to worry about DB2 nonsense beyond its wacky syntax.