support for null queries

This commit is contained in:
Ari Lazier 2016-04-11 13:58:52 -07:00
parent b820b28688
commit 8a77099685
3 changed files with 60 additions and 20 deletions

View File

@ -56,6 +56,7 @@ struct number : seq< minus, sor< float_num, hex_num, int_num > > {};
struct true_value : pegtl_istring_t("true") {};
struct false_value : pegtl_istring_t("false") {};
struct null_value : pegtl_istring_t("null") {};
// key paths
struct key_path : list< seq< sor< alpha, one< '_' > >, star< sor< alnum, one< '_', '-' > > > >, one< '.' > > {};
@ -65,7 +66,7 @@ struct argument_index : plus< digit > {};
struct argument : seq< one< '$' >, must< argument_index > > {};
// expressions and operators
struct expr : sor< dq_string, sq_string, number, argument, true_value, false_value, key_path > {};
struct expr : sor< dq_string, sq_string, number, argument, true_value, false_value, null_value, key_path > {};
struct case_insensitive : pegtl_istring_t("[c]"){};
struct eq : seq< sor< two< '=' >, one< '=' > >, opt< case_insensitive > >{};
@ -236,6 +237,7 @@ EXPRESSION_ACTION(key_path, Expression::Type::KeyPath)
EXPRESSION_ACTION(number, Expression::Type::Number)
EXPRESSION_ACTION(true_value, Expression::Type::True)
EXPRESSION_ACTION(false_value, Expression::Type::False)
EXPRESSION_ACTION(null_value, Expression::Type::Null)
EXPRESSION_ACTION(argument_index, Expression::Type::Argument)
template<> struct action< true_pred >

View File

@ -28,7 +28,7 @@ class Schema;
namespace parser {
struct Expression
{
enum class Type { None, Number, String, KeyPath, Argument, True, False } type;
enum class Type { None, Number, String, KeyPath, Argument, True, False, Null } type;
std::string s;
Expression(Type t = Type::None, std::string s = "") : type(t), s(s) {}
};

View File

@ -265,22 +265,6 @@ void add_link_constraint_to_query(realm::Query &query,
}
}
void add_link_constraint_to_query(realm::Query &query,
Predicate::Operator op,
PropertyExpression &prop_expr,
realm::null) {
precondition(prop_expr.indexes.empty(), "KeyPath queries not supported for object comparisons.");
switch (op) {
case Predicate::Operator::NotEqual:
query.Not();
case Predicate::Operator::Equal:
query.and_query(query.get_table()->column<Link>(prop_expr.prop->table_column).is_null());
break;
default:
throw std::runtime_error("Only 'equal' and 'not equal' operators supported for object comparison.");
}
}
auto link_argument(const PropertyExpression &propExpr, const parser::Expression &argExpr, Arguments &args)
{
return args.object_index_for_argument(stot<int>(argExpr.s));
@ -438,6 +422,50 @@ void do_add_comparison_to_query(Query &query, const Schema &schema, const Object
}
}
}
void do_add_null_comparison_to_query(Query &query, const Schema &schema, const ObjectSchema &object_schema, Predicate::Comparison cmp, const PropertyExpression &expr, Arguments &args)
{
auto type = expr.prop->type;
switch (type) {
case PropertyTypeObject:
precondition(expr.indexes.empty(), "KeyPath queries not supported for object comparisons.");
switch (cmp.op) {
case Predicate::Operator::NotEqual:
query.Not();
case Predicate::Operator::Equal:
query.and_query(query.get_table()->column<Link>(expr.prop->table_column).is_null());
break;
default:
throw std::runtime_error("Only 'equal' and 'not equal' operators supported for object comparison.");
}
break;
case PropertyTypeArray:
throw std::runtime_error((std::string)"Comparing Lists to 'null' is not supported");
break;
default: {
switch (cmp.op) {
case Predicate::Operator::NotEqual:
query.not_equal(expr.prop->table_column, realm::null());
break;
case Predicate::Operator::Equal:
query.equal(expr.prop->table_column, realm::null());
break;
default:
throw std::runtime_error("Only 'equal' and 'not equal' operators supported for object comparison.");
}
}
}
}
bool expression_is_null(const parser::Expression &expr, Arguments &args) {
if (expr.type == parser::Expression::Type::Null) {
return true;
}
else if (expr.type == parser::Expression::Type::Argument) {
return args.is_argument_null(stot<int>(expr.s));
}
return false;
}
void add_comparison_to_query(Query &query, const Predicate &pred, Arguments &args, const Schema &schema, const std::string &type)
{
@ -446,11 +474,21 @@ void add_comparison_to_query(Query &query, const Predicate &pred, Arguments &arg
auto object_schema = schema.find(type);
if (t0 == parser::Expression::Type::KeyPath && t1 != parser::Expression::Type::KeyPath) {
PropertyExpression expr(query, schema, object_schema, cmpr.expr[0].s);
do_add_comparison_to_query(query, schema, *object_schema, cmpr, expr, expr, cmpr.expr[1], args);
if (expression_is_null(cmpr.expr[1], args)) {
do_add_null_comparison_to_query(query, schema, *object_schema, cmpr, expr, args);
}
else {
do_add_comparison_to_query(query, schema, *object_schema, cmpr, expr, expr, cmpr.expr[1], args);
}
}
else if (t0 != parser::Expression::Type::KeyPath && t1 == parser::Expression::Type::KeyPath) {
PropertyExpression expr(query, schema, object_schema, cmpr.expr[1].s);
do_add_comparison_to_query(query, schema, *object_schema, cmpr, expr, cmpr.expr[0], expr, args);
if (expression_is_null(cmpr.expr[0], args)) {
do_add_null_comparison_to_query(query, schema, *object_schema, cmpr, expr, args);
}
else {
do_add_comparison_to_query(query, schema, *object_schema, cmpr, expr, cmpr.expr[0], expr, args);
}
}
else {
throw std::runtime_error("Predicate expressions must compare a keypath and another keypath or a constant value");