protected HqlTreeNode VisitConditionalExpression(ConditionalExpression expression)
{
var test = VisitExpression(expression.Test).AsExpression();
var ifTrue = BooleanToCaseConvertor.ConvertBooleanToCase(VisitExpression(expression.IfTrue).AsExpression());
var ifFalse = (expression.IfFalse != null
? BooleanToCaseConvertor.ConvertBooleanToCase(VisitExpression(expression.IfFalse).AsExpression())
: null);
var @case = _hqlTreeBuilder.Case(new[] { _hqlTreeBuilder.When(test, ifTrue) }, ifFalse);
return((expression.Type == typeof(bool) || expression.Type == (typeof(bool?)))
? (HqlTreeNode)_hqlTreeBuilder.Equality(@case, _hqlTreeBuilder.True())
: _hqlTreeBuilder.Cast(@case, expression.Type));
}
public void Visit(Expression expression)
{
var distinct = expression as NhDistinctExpression;
if (distinct != null)
{
expression = distinct.Expression;
}
// Find the sub trees that can be expressed purely in HQL
var nominator = new SelectClauseHqlNominator(_parameters);
nominator.Visit(expression);
_hqlNodes.UnionWith(nominator.HqlCandidates);
// Linq2SQL ignores calls to local methods. Linq2EF seems to not support
// calls to local methods at all. For NHibernate we support local methods,
// but prevent their use together with server-side distinct, since it may
// end up being wrong.
if (distinct != null && nominator.ContainsUntranslatedMethodCalls)
{
throw new NotSupportedException("Cannot use distinct on result that depends on methods for which no SQL equivalent exist.");
}
// Now visit the tree
var projection = VisitExpression(expression);
if ((projection != expression) && !_hqlNodes.Contains(expression))
{
ProjectionExpression = Expression.Lambda(projection, _inputParameter);
}
// Handle any boolean results in the output nodes
_hqlTreeNodes = BooleanToCaseConvertor.Convert(_hqlTreeNodes).ToList();
if (distinct != null)
{
var treeNodes = new List <HqlTreeNode>(_hqlTreeNodes.Count + 1)
{
_hqlTreeBuilder.Distinct()
};
treeNodes.AddRange(_hqlTreeNodes);
_hqlTreeNodes = new List <HqlExpression>(1)
{
_hqlTreeBuilder.ExpressionSubTreeHolder(treeNodes)
};
}
}
public void Visit(Expression expression)
{
// First, find the sub trees that can be expressed purely in HQL
_hqlNodes = new Nominator(CanBeEvaluatedInHqlSelectStatement, CanBeEvaluatedInHqlStatementShortcut).Nominate(expression);
// Now visit the tree
Expression projection = VisitExpression(expression);
if ((projection != expression) && !_hqlNodes.Contains(expression))
{
ProjectionExpression = Expression.Lambda(projection, _inputParameter);
}
// Finally, handle any boolean results in the output nodes
_hqlTreeNodes = BooleanToCaseConvertor.Convert(_hqlTreeNodes).ToList();
}