Merge pull request #386 from realm/al-null-query

Support for querying against null for optionals

CHANGELOG.md

@@ -1,3 +1,14 @@
+x.x.x Release notes (yyyy-MM-dd)
+=============================================================
+### Breaking changes
+* None
+
+### Enhancements
+* Support for queries comparing optional properties to `null`
+
+### Bugfixes
+* None
+
 0.11.1 Release notes (2016-3-29)
 =============================================================
 ### Bugfixes

src/object-store/src/parser/parser.cpp

@@ -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 >

src/object-store/src/parser/parser.hpp

@@ -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) {}
 };

src/object-store/src/parser/query_builder.cpp

@@ -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));
@@ -439,6 +423,103 @@ void do_add_comparison_to_query(Query &query, const Schema &schema, const Object
     }
 }
   
+template<typename T>
+void do_add_null_comparison_to_query(Query &query, Predicate::Operator op, const PropertyExpression &expr, Arguments &args)
+{
+    Columns<T> column = expr.table_getter()->template column<T>(expr.prop->table_column);
+    switch (op) {
+        case Predicate::Operator::NotEqual:
+            query.and_query(column != realm::null());
+            break;
+        case Predicate::Operator::Equal:
+            query.and_query(column == realm::null());
+            break;
+        default:
+            throw std::runtime_error("Only 'equal' and 'not equal' operators supported when comparing against 'null'.");
+    }
+}
+    
+template<>
+void do_add_null_comparison_to_query<Binary>(Query &query, Predicate::Operator op, const PropertyExpression &expr, Arguments &args)
+{
+    precondition(expr.indexes.empty(), "KeyPath queries not supported for data comparisons.");
+    Columns<Binary> column = expr.table_getter()->template column<Binary>(expr.prop->table_column);
+    switch (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 when comparing against 'null'.");
+    }
+}
+    
+template<>
+void do_add_null_comparison_to_query<Link>(Query &query, Predicate::Operator op, const PropertyExpression &expr, Arguments &args)
+{
+    precondition(expr.indexes.empty(), "KeyPath queries not supported for object comparisons.");
+    switch (op) {
+        case Predicate::Operator::NotEqual:
+            // for not equal we negate the query and then fallthrough
+            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.");
+    }
+}
+
+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 PropertyTypeBool:
+            do_add_null_comparison_to_query<bool>(query, cmp.op, expr, args);
+            break;
+        case PropertyTypeDate:
+            do_add_null_comparison_to_query<DateTime>(query, cmp.op, expr, args);
+            break;
+        case PropertyTypeDouble:
+            do_add_null_comparison_to_query<Double>(query, cmp.op, expr, args);
+            break;
+        case PropertyTypeFloat:
+            do_add_null_comparison_to_query<Float>(query, cmp.op, expr, args);
+            break;
+        case PropertyTypeInt:
+            do_add_null_comparison_to_query<Int>(query, cmp.op, expr, args);
+            break;
+        case PropertyTypeString:
+            do_add_null_comparison_to_query<String>(query, cmp.op, expr, args);
+            break;
+        case PropertyTypeData:
+            do_add_null_comparison_to_query<Binary>(query, cmp.op, expr, args);
+            break;
+        case PropertyTypeObject:
+            do_add_null_comparison_to_query<Link>(query, cmp.op, expr, args);
+            break;
+        case PropertyTypeArray:
+            throw std::runtime_error((std::string)"Comparing Lists to 'null' is not supported");
+            break;
+        default: {
+            throw std::runtime_error((std::string)"Object type " + string_for_property_type(type) + " not supported");
+        }
+    }
+}
+    
+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)
 {
     const Predicate::Comparison &cmpr = pred.cmpr;
@@ -446,12 +527,22 @@ 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);
+        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);
+        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");
     }

src/object-store/tests/query.json

@@ -245,6 +245,9 @@
         ["QueryCount", 1, "LinkObject", "linkCol == $0", [0, "linkCol"]],
         ["QueryCount", 1, "LinkObject", "$0 == linkCol", [1, "linkCol"]],
         ["QueryCount", 2, "LinkObject", "linkCol != $0", [0, "linkCol"]],
+        ["QueryCount", 1, "LinkObject", "linkCol = null"],
+        ["QueryCount", 2, "LinkObject", "linkCol != NULL"],
+        ["QueryCount", 1, "LinkObject", "linkCol = $0", null],
 
         ["QueryThrows", "LinkObject", "linkCol > $0", [0, "linkCol"]],
         ["QueryThrows", "LinkObject", "intCol = $0", [0, "linkCol"]]
@@ -317,6 +320,62 @@
         ["ObjectSet", [1],    "LinkTypesObject", "linkLink.basicLink.floatCol == 0.1"],
         ["ObjectSet", [1, 3], "LinkTypesObject", "linkLink.basicLink.floatCol > 0"]
     ]
+},
+
+"optionalTests" : {
+    "schema" : [
+    { 
+        "name": "OptionalTypesObject",  
+        "primaryKey": "primaryKey",
+        "properties": [
+            { "name": "primaryKey", "type": "int" },
+            { "name": "intCol",     "type": "int",      "optional": true },
+            { "name": "floatCol",   "type": "float",    "optional": true },
+            { "name": "doubleCol",  "type": "double",   "optional": true },
+            { "name": "stringCol",  "type": "string",   "optional": true },
+            { "name": "dateCol",    "type": "date",     "optional": true },
+            { "name": "dataCol",    "type": "data",     "optional": true }
+        ]
+    }, 
+    {
+        "name": "LinkTypesObject",
+        "primaryKey": "primaryKey",
+        "properties": [
+            { "name": "primaryKey", "type": "int" },
+            { "name": "basicLink",  "type": "object", "objectType": "OptionalTypesObject" }
+        ]
+    }],
+    "objects": [
+        { "type": "LinkTypesObject", "value": [0, [0, 1, 0.1, 0.001, "1", 1, [1, 10, 100]]] },
+        { "type": "LinkTypesObject", "value": [1, [1, null, null, null, null, null, null]] }
+    ],
+    "tests": [
+        ["ObjectSet", [1], "OptionalTypesObject", "intCol == null"],
+        ["ObjectSet", [1], "OptionalTypesObject", "null == intCol"],
+        ["ObjectSet", [0], "OptionalTypesObject", "intCol != null"],
+        ["ObjectSet", [1], "OptionalTypesObject", "floatCol == null"],
+        ["ObjectSet", [0], "OptionalTypesObject", "floatCol != null"],
+        ["ObjectSet", [1], "OptionalTypesObject", "doubleCol == null"],
+        ["ObjectSet", [0], "OptionalTypesObject", "doubleCol != null"],
+        ["ObjectSet", [1], "OptionalTypesObject", "stringCol == null"],
+        ["ObjectSet", [0], "OptionalTypesObject", "stringCol != null"],
+        ["ObjectSet", [1], "OptionalTypesObject", "dateCol == null"],
+        ["ObjectSet", [0], "OptionalTypesObject", "dateCol != null"],
+        ["ObjectSet", [1], "OptionalTypesObject", "dataCol == null"],
+        ["ObjectSet", [0], "OptionalTypesObject", "dataCol != null"],
+
+        ["ObjectSet", [1], "LinkTypesObject", "basicLink.intCol == null"],
+        ["ObjectSet", [0], "LinkTypesObject", "basicLink.intCol != null"],
+        ["ObjectSet", [1], "LinkTypesObject", "basicLink.floatCol == null"],
+        ["ObjectSet", [0], "LinkTypesObject", "basicLink.floatCol != null"],
+        ["ObjectSet", [1], "LinkTypesObject", "basicLink.doubleCol == null"],
+        ["ObjectSet", [0], "LinkTypesObject", "basicLink.doubleCol != null"],
+        ["ObjectSet", [1], "LinkTypesObject", "basicLink.stringCol == null"],
+        ["ObjectSet", [0], "LinkTypesObject", "basicLink.stringCol != null"],
+        ["ObjectSet", [1], "LinkTypesObject", "basicLink.dateCol == null"],
+        ["ObjectSet", [0], "LinkTypesObject", "basicLink.dateCol != null"],
+        ["QueryThrows", "LinkTypesObject", "basicLink.dataCol == null"]
+    ]
 }
 
 }

tests/js/query-tests.js

@@ -146,6 +146,9 @@ module.exports = BaseTest.extend({
     },
     testKeyPathQueries: function() {
         runQuerySuite(testCases.keyPathTests);
+    },
+    testOptionalQueries: function() {
+        runQuerySuite(testCases.optionalTests);
     }
 });