string GetField <TP>(Expression <Func <T, TP> > fieldSelector)
{
ExpressionTreeTransformer transformer =
new ExpressionTreeTransformer(fieldSelector);
return(transformer.Transform());
}
/// <summary>
/// Add an expression which represents a relation. The query will try to fetch these related objects together with the main resultset.
/// </summary>
/// <typeparam name="TP">The type of the property - will be automatically determined by the compiler.</typeparam>
/// <param name="expr"></param>
public void AddPrefetch <TP>(Expression <Func <T, TP> > expr)
{
ExpressionTreeTransformer transformer =
new ExpressionTreeTransformer((LambdaExpression)expr);
string field = transformer.Transform();
this.prefetches.Add(field);
}
/// <summary>
/// Implements the Linq orderby ... descending statement
/// </summary>
/// <typeparam name="K"></typeparam>
/// <param name="keySelector"></param>
/// <returns></returns>
public VirtualTable <T> OrderByDescending <K>(Expression <Func <T, K> > keySelector)
{
ExpressionTreeTransformer transformer =
new ExpressionTreeTransformer((LambdaExpression)keySelector);
string field = transformer.Transform();
this.orderings.Add(new Query.DescendingOrder(field));
return(this);
}
/// <summary>
/// Implements the Linq where clause
/// </summary>
/// <param name="expr"></param>
/// <returns></returns>
public VirtualTable <T> Where(Expression <Func <T, bool> > expr)
{
// Transform the expression to NDOql
ExpressionTreeTransformer transformer = new ExpressionTreeTransformer((LambdaExpression)expr);
this.queryString = transformer.Transform();
this.queryParameters.Clear();
// Add the parameters collected by the transformer
foreach (object o in transformer.Parameters)
{
this.queryParameters.Add(o);
}
return(this);
}
