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 int Visit(SqlSubqueryScalarExpression sqlSubqueryScalarExpression)
{
int hashCode = SqlSubqueryScalarExpressionHashCode;
hashCode = CombineHashes(hashCode, sqlSubqueryScalarExpression.Query.Accept(this));
return(hashCode);
}
public override SqlObject VisitSubqueryScalarExpression([NotNull] sqlParser.SubqueryScalarExpressionContext context)
{
Contract.Requires(context != null);
// '(' sql_query ')'
SqlQuery subquery = (SqlQuery)this.Visit(context.sql_query());
return(SqlSubqueryScalarExpression.Create(subquery));
}
public override bool Visit(SqlSubqueryScalarExpression first, SqlObject secondAsObject)
{
if (!(secondAsObject is SqlSubqueryScalarExpression second))
{
return(false);
}
if (!Equals(first.Query, second.Query))
{
return(false);
}
return(true);
}
public void SqlSubqueryScalarExpressionTest()
{
SqlLiteralScalarExpression five = SqlLiteralScalarExpression.Create(SqlNumberLiteral.Create(5));
SqlLiteralScalarExpression three = SqlLiteralScalarExpression.Create(SqlNumberLiteral.Create(3));
// (SELECT VALUE 5 + 3)
SqlSubqueryScalarExpression subqueryScalarExpression = SqlSubqueryScalarExpression.Create(
SqlQuery.Create(
SqlSelectClause.Create(
SqlSelectValueSpec.Create(
SqlBinaryScalarExpression.Create(
SqlBinaryScalarOperatorKind.Add,
five,
three))),
fromClause: null,
whereClause: null,
groupByClause: null,
orderByClause: null,
offsetLimitClause: null));
AssertEvaluation(CosmosNumber64.Create(5 + 3), subqueryScalarExpression);
}
public abstract void Visit(SqlSubqueryScalarExpression sqlObject);
public override void Visit(SqlSubqueryScalarExpression sqlSubqueryScalarExpression)
{
this.WriteStartContext("(");
sqlSubqueryScalarExpression.Query.Accept(this);
this.WriteEndContext(")");
}
public override SqlObject Visit(SqlSubqueryScalarExpression sqlSubqueryScalarExpression)
{
return(SqlSubqueryScalarExpression.Create(sqlSubqueryScalarExpression.Query.Accept(this) as SqlQuery));
}
public abstract void Visit(SqlSubqueryScalarExpression scalarExpression);
public override bool Visit(SqlSubqueryScalarExpression sqlSubqueryScalarExpression)
{
// No need to worry about the aggregates within the subquery since they get recursively evaluated.
return(false);
}
public abstract TResult Visit(SqlSubqueryScalarExpression sqlObject);
public override bool Visit(SqlSubqueryScalarExpression scalarExpression)
{
return(false);
}
public abstract TOutput Visit(SqlSubqueryScalarExpression sqlObject, TArg input);
public abstract TResult Visit(SqlSubqueryScalarExpression scalarExpression);
