protected override ScalarExpression OnBuildQuery(QueryBuilderContext context)
{
// Currently this must be a literal
var field = Right as ConstantEntityNode;
if (field == null)
{
throw new ParseException("Field required.");
}
var queryNode = context.GetNode(Left);
// Start workaround for #27148
// If an aggregate operation is performed on a choice field, then we try to treat it like an entity
// then we have a scenario that can't currently be represented in structured queries.
// (Because sq aggregate operations get declared as expressions, but if it's an expression we can no longer use it as a sq node for other expressions).
// This can happen if we use the choice-field in a comparison (e.g. max(choice)>whatever) because the compiler
// will inject a field lookup to redirect to the ordering field.
// For now, detect this specific scenario, and pass the aggregate expression directly through because the query engine
// will defer to the ordering version of the SQL, which will in turn look up the enumOrder field.
// However, ideally we should also be able to do things like max(choice).someOtherRelationshipOrField
bool nodeIsAggregate = Left is AggregateNode || Left is EntityTypeCast && Left.Arguments[0] is AggregateNode;
bool fieldIsEnumOrdering = field.Instance.Id == WellKnownAliases.CurrentTenant.EnumOrder;
if (nodeIsAggregate && fieldIsEnumOrdering)
{
return(Left.BuildQuery(context));
}
// End workaround
var result = new ResourceDataColumn
{
FieldId = field.Instance,
NodeId = queryNode.NodeId
};
return(result);
}
protected override ScalarExpression OnBuildQuery(QueryBuilderContext context)
{
ScalarExpression arg = Argument.BuildQuery(context);
if (ResultType.Type == DataType.Entity)
{
return(arg);
}
// Special case for AggregateExpression, because if we aggregate a choicefield, then it presents
// as an Entity type, therefore requesting this cast - but the query builder wants to receive the aggregate expression directly.
if (arg is EDC.ReadiNow.Metadata.Query.Structured.AggregateExpression)
{
var result = new MutateExpression {
Expression = arg
};
switch (ResultType.Type)
{
case DataType.String:
result.MutateType = MutateType.DisplaySql;
break;
case DataType.Bool:
result.MutateType = MutateType.BoolSql;
break;
default:
throw new InvalidOperationException(ResultType.Type.ToString( ));
}
return(result);
}
// Just refer to the node
var queryNode = context.GetNode(Argument);
switch (ResultType.Type)
{
case DataType.String:
var nameResult = new ResourceDataColumn
{
FieldId = "core:name",
NodeId = queryNode.NodeId
};
return(nameResult);
case DataType.Bool:
var boolResult = new CalculationExpression
{
Operator = CalculationOperator.IsNull,
Expressions = new List <ScalarExpression>
{
new IdExpression {
NodeId = queryNode.NodeId
}
}
};
return(boolResult);
default:
throw new InvalidOperationException(ResultType.Type.ToString());
}
}