public override CosmosElement Visit(SqlSubqueryScalarExpression scalarExpression, CosmosElement document)
{
// Only run on the current document since the subquery is always correlated.
IEnumerable <CosmosElement> subqueryResults = SqlInterpreter.ExecuteQuery(
new CosmosElement[] { document },
scalarExpression.Query);
CosmosElement result;
int cardinality = subqueryResults.Count();
if (cardinality > 1)
{
throw new ArgumentException("The cardinality of a subquery can not exceed 1.");
}
else if (cardinality == 1)
{
result = subqueryResults.First();
}
else
{
// cardinality = 0
result = Undefined;
}
return(result);
}
public override CosmosElement Visit(SqlExistsScalarExpression scalarExpression, CosmosElement document)
{
// Only run on the current document since the subquery is always correlated.
IEnumerable <CosmosElement> subqueryResults = SqlInterpreter.ExecuteQuery(
new CosmosElement[] { document },
scalarExpression.Subquery);
return(CosmosBoolean.Create(subqueryResults.Any()));
}
public override CosmosElement Visit(
SqlArrayScalarExpression scalarExpression,
CosmosElement document)
{
// Only run on the current document since the subquery is always correlated.
IEnumerable <CosmosElement> subqueryResults = SqlInterpreter.ExecuteQuery(
new CosmosElement[] { document },
scalarExpression.SqlQuery);
List <CosmosElement> arrayScalarResult = new List <CosmosElement>();
foreach (CosmosElement subQueryResult in subqueryResults)
{
arrayScalarResult.Add(subQueryResult);
}
return(CosmosArray.Create(subqueryResults));
}
public override CollectionEvaluationResult Visit(SqlSubqueryCollection collection, IEnumerable <CosmosElement> input)
{
List <Tuple <CosmosElement, string> > subDocumentsAndRids = new List <Tuple <CosmosElement, string> >();
foreach (CosmosObject document in input)
{
string rid = ((CosmosString)document["_rid"]).Value;
IEnumerable <CosmosElement> subqueryResults = SqlInterpreter.ExecuteQuery(
new CosmosElement[] { document },
collection.Query);
foreach (CosmosElement subqueryResult in subqueryResults)
{
subDocumentsAndRids.Add(new Tuple <CosmosElement, string>(subqueryResult, rid));
}
}
return(new CollectionEvaluationResult(subDocumentsAndRids, null));
}