private CodeExpression VisitJoinExpressionBase(LinqJoinExpressionBase expression, string codeMethodName)
{
var outer = this.GenerateCode(expression.Outer);
var inner = this.GenerateCode(expression.Inner);
var outerKeySelector = this.GenerateCode(expression.OuterKeySelector);
var innerKeySelector = this.GenerateCode(expression.InnerKeySelector);
var resultSelector = this.GenerateCode(expression.ResultSelector);
return(outer.Call(codeMethodName, inner, outerKeySelector, innerKeySelector, resultSelector));
}
private QueryValue EvaluateJoinExpression(LinqJoinExpressionBase expression, bool isGroupJoin)
{
var outer = this.EvaluateCollection(expression.Outer);
var inner = this.EvaluateCollection(expression.Inner);
var outerKeys = this.EvaluateKeysForJoin(outer, expression.OuterKeySelector);
var innerKeys = this.EvaluateKeysForJoin(inner, expression.InnerKeySelector);
// Dictionary: inner key -> a list of inner values with this key
Dictionary <QueryScalarValue, IList <QueryValue> > innerKeyLookup = this.BuildInnerKeyLookup(inner, innerKeys);
List <QueryValue> joinResultElements = new List <QueryValue>();
for (int outerIndex = 0; outerIndex < outer.Elements.Count; outerIndex++)
{
ExceptionUtilities.Assert(outerKeys.Elements[outerIndex] is QueryScalarValue, "For now we only support join on primitive keys.");
var outerKey = (QueryScalarValue)outerKeys.Elements[outerIndex];
IList <QueryValue> innerMatches;
if (!innerKeyLookup.TryGetValue(outerKey, out innerMatches))
{
innerMatches = new List <QueryValue>();
}
if (isGroupJoin)
{
QueryValue result = this.EvaluateLambda <QueryValue>(expression.ResultSelector, outer.Elements[outerIndex], inner.Type.CreateCollectionWithValues(innerMatches));
joinResultElements.Add(result);
}
else
{
foreach (var innerValue in innerMatches)
{
QueryValue result = this.EvaluateLambda <QueryValue>(expression.ResultSelector, outer.Elements[outerIndex], innerValue);
joinResultElements.Add(result);
}
}
}
var resultType = expression.ResultSelector.Body.ExpressionType;
return(new QueryCollectionValue(resultType.CreateCollectionType(), resultType.EvaluationStrategy, QueryError.GetErrorFromValues(joinResultElements), joinResultElements));
}
private QueryExpression VisitJoinExpressionBase(LinqJoinExpressionBase expression, Func <QueryExpression, QueryExpression, LinqLambdaExpression, LinqLambdaExpression, LinqLambdaExpression, QueryType, QueryExpression> builderFunc)
{
var outer = this.ReplaceExpression(expression.Outer);
var inner = this.ReplaceExpression(expression.Inner);
var outerKeySelector = (LinqLambdaExpression)this.ReplaceExpression(expression.OuterKeySelector);
var innerKeySelector = (LinqLambdaExpression)this.ReplaceExpression(expression.InnerKeySelector);
var resultSelector = (LinqLambdaExpression)this.ReplaceExpression(expression.ResultSelector);
if (HasChanged(expression.Outer, outer) ||
HasChanged(expression.Inner, inner) ||
HasChanged(expression.OuterKeySelector, outerKeySelector) ||
HasChanged(expression.InnerKeySelector, innerKeySelector) ||
HasChanged(expression.ResultSelector, resultSelector))
{
return(builderFunc(outer, inner, outerKeySelector, innerKeySelector, resultSelector, expression.ExpressionType));
}
return(expression);
}
