NHibernate.Exceptions.GenericADOException : could not execute query

Question

I have a legacy application (vfp 8) that I need to pull data from (no inserts). I am using the Accnum field as the primary key, it is defined in the table as character 11.

Factory configuration:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-configuration xmlns="urn:nhibernate-configuration-2.2">
<reflection-optimizer use="false" />
<session-factory>
<property name="connection.provider">NHibernate.Connection.DriverConnectionProvider</property>
<property name="dialect">NHibernate.Dialect.GenericDialect</property>
<property name="connection.driver_class">NHibernate.Driver.OleDbDriver</property>
<property name="connection.connection_string">Provider=VFPOLEDB.1;Data Source=C:\Analysis\Quantium\development\RD warehouse\_RDAUWH\Data;Collating Sequence=MACHINE</property>
<property name="show_sql">false</property>
</session-factory>
</hibernate-configuration>

This is my mapping file:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
               assembly="RDLabels"
               namespace="RDLabels.Domain">

  <class name="CustMast">
    <id name="Accnum" column="Accnum" type="string">
    <generator class="assigned"/>
    </id>
    <property name="Fullname" />
    <property name="Add" />
    <property name="State" />
  </class>  
</hibernate-mapping>

The class:

public class CustMast
{
    private string _accnum;
    public virtual string Accnum
    {
        get { return _accnum; }
        set { _accnum = value; }
    }
    private string _fullname;
    public virtual string Fullname
    {
        get { return _fullname; }
        set { _fullname = value; }
    }
    private string _add;
    public virtual string Add
    {
        get { return _add; }
        set { _add = value; }
    }
    private string _state;
    public virtual string State
    {
        get { return _state; }
        set { _state = value; }
    }
}

Here is the code that gets the record:

public CustMast GetByAccnum(String accnum)
{
        using (ISession session = NHibernateHelper.OpenSession())
        {
            CustMast custMast = session
                                .CreateCriteria(typeof(CustMast))
                                .Add(Restrictions.Eq("Accnum", accnum))
                                .UniqueResult<CustMast>();
            return custMast;
        }
}

The full error is:

NHibernate.Exceptions.GenericADOException : could not execute query
[ SELECT this_.Accnum as Accnum0_0_, this_.Fullname as Fullname0_0_, this_.Add as Add0_0_, this_.State as State0_0_ FROM CustMast this_ WHERE this_.Accnum = ? ]
Name:cp0 - Value:00059337444
[SQL: SELECT this_.Accnum as Accnum0_0_, this_.Fullname as Fullname0_0_, this_.Add as Add0_0_, this_.State as State0_0_ FROM CustMast this_ WHERE this_.Accnum = ?]
----> System.IndexOutOfRangeException : Invalid index 0 for this OleDbParameterCollection with Count=0. - d:\CSharp\NH\NH\nhibernate\src\NHibernate\Loader\Loader.cs:1590

Running NHibernate Profiler it shows:

WARN: 
reflection-optimizer property is ignored out of application configuration file.


WARN: 
System.IndexOutOfRangeException: Invalid index 0 for this OleDbParameterCollection with Count=0.
at System.Data.OleDb.OleDbParameterCollection.RangeCheck(Int32 index)
at System.Data.OleDb.OleDbParameterCollection.GetParameter(Int32 index)
at System.Data.Common.DbParameterCollection.System.Collections.IList.get_Item(Int32 index)
at NHibernate.Driver.DriverBase.ExpandQueryParameters(IDbCommand cmd, SqlString sqlString) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Driver\DriverBase.cs:line 235
at NHibernate.AdoNet.AbstractBatcher.ExpandQueryParameters(IDbCommand cmd, SqlString sqlString) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\AdoNet\AbstractBatcher.cs:line 232
at NHibernate.Loader.Loader.PrepareQueryCommand(QueryParameters queryParameters, Boolean scroll, ISessionImplementor session) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Loader\Loader.cs:line 1152

ERROR: 
Invalid index 0 for this OleDbParameterCollection with Count=0.

Answer 1

I was struggling with my linq queries throwing the same error whenever i passed them a parameter. If i didn't pass any parameters and did a session.Query() they would work fine.

I struggled with this for days but i found this Nhibernate jira ticket here . It explains an apparent problem with SQLParameters and the Iseries Db2 provider.

I understand you're using a different provider but you might benefit from just downloading the latest Nhibernate core source code, building it, and referencing the latest version in your project. It fixed my issue.