Get Entity by Primary Key v2.0

EntiyByPrimaryKey.cs

public TEntity GetEntityByPrimaryKey(object pkKey, params object[] pkKeys)
{
    List<object> primaryKeys = new List<object>();
    primaryKeys.Add(pkKey);
    primaryKeys.AddRange(pkKeys);
 
    TEntity entity = null;
    Type entityType = typeof(TEntity);
 
    using (DataContext dataContext = new DataContext(this._DbConnection))
    {
        dataContext.Log = new DebuggerWriter();
        dataContext.ObjectTrackingEnabled = false;
 
        Table<TEntity> table = dataContext.GetTable<TEntity>();
 
        MetaType metaEntityType = dataContext.Mapping.GetMetaType(entityType);
 
        var primaryKeyColumns = from pkColumn in metaEntityType.DataMembers
                                where pkColumn.IsPrimaryKey
                                select pkColumn;
 
        int pkColumnsCount = 0;
 
        if (primaryKeyColumns != null)
            pkColumnsCount = primaryKeyColumns.Count();
 
        if (pkColumnsCount == 0)
            throw new InvalidOperationException("Table doesn't have primary key");
 
        if (pkColumnsCount != primaryKeys.Count)
            throw new InvalidOperationException("Primary key value doesn't match primary key columns.");
 
        ParameterExpression paramExpression = Expression.Parameter(entityType, "entity");
 
        BinaryExpression whereExpression = null;
 
        int index = 0;
 
        foreach (MetaDataMember pkColumn in primaryKeyColumns)
        {
            object value = primaryKeys[index];
            string columnName = pkColumn.Name;
 
            if (value != null && value.GetType() != pkColumn.Type)
            {
                Type paramType = value.GetType();
                string exceptionMsg = String.Format("The type '{0}' of parameter '{1}' is different than its column '{2}' type '{3}'", paramType, value, columnName, pkColumn.Type);
                throw new InvalidOperationException(exceptionMsg);
            }
 
            BinaryExpression condition = Expression.Equal(Expression.Property(paramExpression, columnName), Expression.Constant(value));
 
            if (whereExpression != null)
                whereExpression = Expression.And(whereExpression, condition);
            else
                whereExpression = condition;
 
            index++;
        }
 
        Expression<Func<TEntity, bool>> predicate = Expression.Lambda<Func<TEntity, bool>>(whereExpression, new ParameterExpression[] { paramExpression });
        entity = table.SingleOrDefault(predicate);
    }
 
    return entity;
}