public void SelectCount(Expression condition)
{
SelectNode = new CountSelectNode(this);
if (condition != null)
{
WhereNodes.Add(new WhereNode(condition.GetLambda(), FromNode.Alias, this));
}
}
public void SelectSingle(Expression condition, bool allowDefault)
{
AllowDefault = allowDefault;
Take = new ConstantNode(Expression.Constant(1), this);
if (condition != null)
{
WhereNodes.Add(new WhereNode(condition.GetLambda(), FromNode.Alias, this));
}
}
private void DoVisit(MethodCallExpression expression)
{
switch (expression.Method.Name)
{
case "Where":
WhereNodes.Add(new WhereNode(expression.Arguments[1].GetLambda(), FromNode.Alias, this));
Visit(expression.Arguments[0]);
break;
case "OrderBy":
case "OrderByDescending":
case "ThenBy":
case "ThenByDescending":
Visit(expression.Arguments[0]);
break;
default:
throw new InvalidOperationException(string.Format("Method {0} is not valid for {1}", expression.Method.GetFriendlyName(), GetType().GetFriendlyName()));
}
}
public void Where(LambdaExpression lambda)
{
WhereNodes.Add(new WhereNode(lambda, FromNode.Alias, this));
}
private void DoVisit(MethodCallExpression expression)
{
switch (expression.Method.Name)
{
case "Where": _actions.Push(() => WhereNodes.Add(new WhereNode(expression.Arguments[1].GetLambda(), FromNode.Alias, this)));
Visit(expression.Arguments[0]);
break;
case "OrderBy":
case "ThenBy":
_actions.Push(() => OrderBy(expression.Arguments[1], SortDir.Asc));
Visit(expression.Arguments[0]);
break;
case "OrderByDescending":
case "ThenByDescending":
_actions.Push(() => OrderBy(expression.Arguments[1], SortDir.Desc));
Visit(expression.Arguments[0]);
break;
case "First":
case "Single":
_actions.Push(() => SelectSingle(expression.GetArgumentOrDefault(1), false));
Visit(expression.Arguments[0]);
break;
case "FirstOrDefault":
case "SingleOrDefault":
_actions.Push(() => SelectSingle(expression.GetArgumentOrDefault(1), true));
Visit(expression.Arguments[0]);
break;
case "Count":
_actions.Push(() => SelectCount(expression.GetArgumentOrDefault(1)));
Visit(expression.Arguments[0]);
break;
case "Select":
Select(expression);
break;
case "Sum":
_actions.Push(() => SelectNode = new SumSelectNode(expression.Arguments[1].GetLambda(), this));
Visit(expression.Arguments[0]);
break;
case "Skip":
_actions.Push(() => Skip = For(expression.Arguments[1]));
Visit(expression.Arguments[0]);
break;
case "Distinct":
_actions.Push(() => Distinct = true);
Visit(expression.Arguments[0]);
break;
case "Take":
_actions.Push(() => Take = For(expression.Arguments[1]));
Visit(expression.Arguments[0]);
break;
default: throw new InvalidOperationException(string.Format("Don't know how to parse method {0}", expression.Method.GetFriendlyName()));
}
}