revert null printing

src/common/types/value.cpp

@@ -357,7 +357,7 @@ Value Value::createValue(const char* value) {
 
 string Value::toString() const {
     if (isNull_) {
-        return "NULL";
+        return "";
     }
     switch (dataType.typeID) {
     case BOOL:

test/demo_db/demo_db_test.cpp

@@ -28,7 +28,7 @@ TEST_F(DemoDBTest, CreateAvgNullTest) {
     auto result =
         conn->query("MATCH (a:User) WITH a, avg(a.age) AS b, SUM(a.age) AS c, COUNT(a.age) AS d, "
                     "COUNT(*) AS e RETURN a, b, c,d, e ORDER BY c DESC");
-    auto groundTruth = vector<string>{"(0:4:User {name:Alice, age:NULL})|NULL|NULL|0|1",
+    auto groundTruth = vector<string>{"(0:4:User {name:Alice, age:})|||0|1",
         "(0:2:User {name:Zhang, age:50})|50.000000|50|1|1",
         "(0:1:User {name:Karissa, age:40})|40.000000|40|1|1",
         "(0:0:User {name:Adam, age:30})|30.000000|30|1|1",
@@ -63,6 +63,6 @@ TEST_F(DemoDBTest, SetNodeTest) {
     ASSERT_EQ(TestHelper::convertResultToString(*result, true /* check order */), groundTruth);
     ASSERT_TRUE(conn->query("MATCH (u:User) WHERE u.name = 'Adam' SET u.age = NULL")->isSuccess());
     result = conn->query("MATCH (u:User) WHERE u.name='Adam' RETURN u.age");
-    groundTruth = vector<string>{"NULL"};
+    groundTruth = vector<string>{""};
     ASSERT_EQ(TestHelper::convertResultToString(*result, true /* check order */), groundTruth);
 }

test/runner/e2e_delete_create_transaction_test.cpp

@@ -501,7 +501,7 @@ static void validateInsertedRel(
     auto length = to_string(param);
     auto place = to_string(param);
     if (testNullAndLongString) {
-        length = "NULL";
+        length = "";
         place = CreateRelTrxTest::getLongStr(place);
     }
     auto groundTruth = length + "|" + place + "|[" + to_string(param) + "]";

test/runner/e2e_set_transaction_test.cpp

@@ -70,15 +70,15 @@ TEST_F(SetNodeStructuredPropTransactionTest,
     conn->beginWriteTransaction();
     readAndAssertNodeProperty(conn.get(), 0 /* node offset */, "age", vector<string>{"35"});
     conn->query("MATCH (a:person) WHERE a.ID = 0 SET a.age = null;");
-    readAndAssertNodeProperty(conn.get(), 0 /* node offset */, "age", vector<string>{"NULL"});
+    readAndAssertNodeProperty(conn.get(), 0 /* node offset */, "age", vector<string>{""});
 }
 
 TEST_F(SetNodeStructuredPropTransactionTest,
     SingleTransactionReadWriteToStringStructuredNodePropertyNullTest) {
     conn->beginWriteTransaction();
     readAndAssertNodeProperty(conn.get(), 0 /* node offset */, "fName", vector<string>{"Alice"});
     auto result = conn->query("MATCH (a:person) WHERE a.ID = 0 SET a.fName = null;");
-    readAndAssertNodeProperty(conn.get(), 0 /* node offset */, "fName", vector<string>{"NULL"});
+    readAndAssertNodeProperty(conn.get(), 0 /* node offset */, "fName", vector<string>{""});
 }
 
 TEST_F(SetNodeStructuredPropTransactionTest,

test/runner/e2e_update_node_test.cpp

@@ -118,8 +118,7 @@ TEST_F(TinySnbUpdateTest, SetNodeIntervalPropTest) {
 TEST_F(TinySnbUpdateTest, SetNodePropNullTest) {
     conn->query("MATCH (a:person) SET a.age=null");
     auto result = conn->query("MATCH (a:person) RETURN a.age");
-    auto groundTruth =
-        vector<string>{"NULL", "NULL", "NULL", "NULL", "NULL", "NULL", "NULL", "NULL"};
+    auto groundTruth = vector<string>{"", "", "", "", "", "", "", ""};
     ASSERT_EQ(TestHelper::convertResultToString(*result), groundTruth);
 }
 
@@ -155,8 +154,7 @@ TEST_F(TinySnbUpdateTest, SetTwoHopTest) {
 TEST_F(TinySnbUpdateTest, SetTwoHopNullTest) {
     conn->query("MATCH (a:person)-[:knows]->(b:person)-[:knows]->(c:person) SET a.age=null");
     auto result = conn->query("MATCH (a:person) RETURN a.ID, a.age");
-    auto groundTruth =
-        vector<string>{"0|NULL", "10|83", "2|NULL", "3|NULL", "5|NULL", "7|20", "8|25", "9|40"};
+    auto groundTruth = vector<string>{"0|", "10|83", "2|", "3|", "5|", "7|20", "8|25", "9|40"};
     ASSERT_EQ(TestHelper::convertResultToString(*result), groundTruth);
 }
 
@@ -166,8 +164,8 @@ TEST_F(TinySnbUpdateTest, InsertNodeWithBoolIntDoubleTest) {
     conn->query("CREATE (:person {ID:80, isWorker:true,age:22,eyeSight:1.1});");
     auto result = conn->query("MATCH (a:person) WHERE a.ID > 8 "
                               "RETURN a.ID, a.gender,a.isStudent, a.isWorker, a.age, a.eyeSight");
-    auto groundTruth = vector<string>{"10|2|False|True|83|4.900000",
-        "80|NULL|NULL|True|22|1.100000", "9|2|False|False|40|4.900000"};
+    auto groundTruth = vector<string>{
+        "10|2|False|True|83|4.900000", "80|||True|22|1.100000", "9|2|False|False|40|4.900000"};
     ASSERT_EQ(TestHelper::convertResultToString(*result), groundTruth);
 }
 
@@ -218,10 +216,10 @@ TEST_F(TinySnbUpdateTest, InsertNodeWithMixedLabelTest) {
 TEST_F(TinySnbUpdateTest, InsertNodeAfterMatchListTest) {
     conn->query("MATCH (a:person) CREATE (:person {ID:a.ID+11, age:a.age*2});");
     auto result = conn->query("MATCH (a:person) RETURN a.ID, a.fName,a.age");
-    auto groundTruth = vector<string>{"0|Alice|35",
-        "10|Hubert Blaine Wolfeschlegelsteinhausenbergerdorff|83", "11|NULL|70", "13|NULL|60",
-        "14|NULL|90", "16|NULL|40", "18|NULL|40", "19|NULL|50", "20|NULL|80", "21|NULL|166",
-        "2|Bob|30", "3|Carol|45", "5|Dan|20", "7|Elizabeth|20", "8|Farooq|25", "9|Greg|40"};
+    auto groundTruth =
+        vector<string>{"0|Alice|35", "10|Hubert Blaine Wolfeschlegelsteinhausenbergerdorff|83",
+            "11||70", "13||60", "14||90", "16||40", "18||40", "19||50", "20||80", "21||166",
+            "2|Bob|30", "3|Carol|45", "5|Dan|20", "7|Elizabeth|20", "8|Farooq|25", "9|Greg|40"};
     ASSERT_EQ(TestHelper::convertResultToString(*result), groundTruth);
 }
 
@@ -244,7 +242,7 @@ TEST_F(TinySnbUpdateTest, InsertSingleNTo1RelTest) {
                 "CREATE (a)-[:studyAt {year:2022}]->(b);");
     auto groundTruth = vector<string>{
         "8|325|(0:5)-[{_id:16, year:2020, places:[awndsnjwejwen,isuhuwennjnuhuhuwewe]}]->(1:0)|16",
-        "9|934|(0:6)-[{_id:40, year:2022, places:NULL}]->(1:1)|40"};
+        "9|934|(0:6)-[{_id:40, year:2022, places:}]->(1:1)|40"};
     auto result = conn->query("MATCH (a:person)-[e:studyAt]->(b:organisation) WHERE a.ID > 5 "
                               "RETURN a.ID, b.orgCode, e, ID(e)");
     ASSERT_EQ(TestHelper::convertResultToString(*result), groundTruth);
@@ -304,21 +302,21 @@ TEST_F(TinySnbUpdateTest, DeleteNodeAfterInsertTest) { // test reset of property
     conn->query("MATCH (a:person) WHERE a.ID = 100 DELETE a;");
     conn->query("CREATE (a:person {ID:101})");
     auto result = conn->query("MATCH (a:person) WHERE a.ID = 101 RETURN a.ID, a.fName, a.age");
-    auto groundTruth = vector<string>{"101|NULL|NULL"};
+    auto groundTruth = vector<string>{"101||"};
     ASSERT_EQ(TestHelper::convertResultToString(*result), groundTruth);
 }
 
 TEST_F(TinySnbUpdateTest, MixedDeleteInsertTest) {
     conn->query("CREATE (a:organisation {ID:30, mark:3.3})");
     auto result = conn->query("MATCH (a:organisation) WHERE a.ID = 30 RETURN a.orgCode, a.mark");
-    auto groundTruth = vector<string>{"NULL|3.300000"};
+    auto groundTruth = vector<string>{"|3.300000"};
     ASSERT_EQ(TestHelper::convertResultToString(*result), groundTruth);
     conn->query("MATCH (a:organisation) WHERE a.ID = 30 DELETE a");
     result = conn->query("MATCH (a:organisation) WHERE a.ID = 30 RETURN a.orgCode, a.mark");
     groundTruth = vector<string>{};
     ASSERT_EQ(TestHelper::convertResultToString(*result), groundTruth);
     conn->query("CREATE (a:organisation {ID:30, orgCode:33})");
     result = conn->query("MATCH (a:organisation) WHERE a.ID = 30 RETURN a.orgCode, a.mark");
-    groundTruth = vector<string>{"33|NULL"};
+    groundTruth = vector<string>{"33|"};
     ASSERT_EQ(TestHelper::convertResultToString(*result), groundTruth);
 }

test/runner/e2e_update_rel_test.cpp

@@ -43,10 +43,10 @@ class UpdateRelTest : public DBTest {
         auto result = conn->query("MATCH (a:animal)-[e:knows]->(:person) where a.ID >= 20 and a.ID "
                                   "<= 30 return e.length");
         auto actualResult = TestHelper::convertResultToString(*result);
-        vector<string> expectedResult = isCommit ? vector<string>{"NULL", "21", "22", "23", "24",
-                                                       "210", "26", "27", "28", "29", "300"} :
-                                                   vector<string>{"20", "21", "22", "23", "24",
-                                                       "25", "26", "27", "28", "29", "30"};
+        vector<string> expectedResult =
+            isCommit ?
+                vector<string>{"", "21", "22", "23", "24", "210", "26", "27", "28", "29", "300"} :
+                vector<string>{"20", "21", "22", "23", "24", "25", "26", "27", "28", "29", "30"};
         sortAndCheckTestResults(actualResult, expectedResult);
     }
 
@@ -70,7 +70,7 @@ class UpdateRelTest : public DBTest {
         auto actualResult = TestHelper::convertResultToString(*result);
         auto expectedResult =
             isCommit ? vector<string>{"990990990", "989", "988988988", "987", "986986986",
-                           "waterloo", "kitchener", "983", "982982982", "NULL", "980980980"} :
+                           "waterloo", "kitchener", "983", "982982982", "", "980980980"} :
                        vector<string>{"990990990", "989", "988988988", "987", "986986986", "985",
                            "984984984", "983", "982982982", "981", "980980980"};
         sortAndCheckTestResults(actualResult, expectedResult);
@@ -96,7 +96,7 @@ class UpdateRelTest : public DBTest {
         auto actualResult = TestHelper::convertResultToString(*result);
         auto expectedResult =
             isCommit ? vector<string>{"[960960960]", "[959]", "[958958958]",
-                           "[updated property1,50]", "[956956956]", "[955]", "[954954954]", "NULL",
+                           "[updated property1,50]", "[956956956]", "[955]", "[954954954]", "",
                            "[952952952]", "[updated property3,54]", "[950950950]"} :
                        vector<string>{"[960960960]", "[959]", "[958958958]", "[957]", "[956956956]",
                            "[955]", "[954954954]", "[953]", "[952952952]", "[951]", "[950950950]"};
@@ -155,7 +155,7 @@ class UpdateRelTest : public DBTest {
         auto result =
             conn->query("MATCH (p:person)-[e:knows]->(:person) where p.ID > 4 return e.length");
         auto actualResult = TestHelper::convertResultToString(*result);
-        auto expectedResult = isCommit ? vector<string>{"NULL", "55", "201"} : vector<string>{};
+        auto expectedResult = isCommit ? vector<string>{"", "55", "201"} : vector<string>{};
         sortAndCheckTestResults(actualResult, expectedResult);
     }
 
@@ -169,7 +169,7 @@ class UpdateRelTest : public DBTest {
             conn->query("MATCH (a:animal)-[e1:knows]->(p:person)-[e2:knows]->(p1:person) WHERE "
                         "p1.ID = 2500 AND a.ID = 5 RETURN e1.length, e2.length");
         auto actualResult = TestHelper::convertResultToString(*result);
-        auto expectedResult = isCommit ? vector<string>{"300|NULL"} : vector<string>{"5|7497"};
+        auto expectedResult = isCommit ? vector<string>{"300|"} : vector<string>{"5|7497"};
         sortAndCheckTestResults(actualResult, expectedResult);
     }
 
@@ -252,7 +252,7 @@ class UpdateRelTest : public DBTest {
         ASSERT_TRUE(conn->query(getUpdateRelQuery("person" /* srcTable */, "person" /* relation */,
             "teaches" /* relation */, 33 /* srcID */, 3 /* dstID */, "SET e.length = 312")));
         commitOrRollbackConnectionAndInitDBIfNecessary(isCommit, transactionTestType);
-        auto expectedResult = isCommit ? vector<string>{"11", "NULL", "22", "31", "512", "312"} :
+        auto expectedResult = isCommit ? vector<string>{"11", "", "22", "31", "512", "312"} :
                                          vector<string>{"11", "21", "22", "31", "32", "33"};
         auto result = conn->query("MATCH (p:person)-[e:teaches]->(:person) RETURN e.length");
         auto actualResult = TestHelper::convertResultToString(*result);
@@ -270,7 +270,7 @@ class UpdateRelTest : public DBTest {
         commitOrRollbackConnectionAndInitDBIfNecessary(isCommit, transactionTestType);
         auto expectedResult =
             isCommit ? vector<string>{"1999", "kuzu", "1997", "db", "1995", "199419941994", "1993",
-                           "NULL", "1991", "1989"} :
+                           "", "1991", "1989"} :
                        vector<string>{"1999", "199819981998", "1997", "199619961996", "1995",
                            "199419941994", "1993", "199219921992", "1991", "1989"};
         auto result = conn->query("MATCH (:animal)-[e:hasOwner]->(:person) RETURN e.place");

test/test_files/copy/copy_node.test

@@ -31,7 +31,7 @@
 -NAME EmptyStringTest
 -QUERY MATCH (row:tableOfTypes) WHERE row.id = 49992 RETURN *;
 ---- 1
-(0:49992:tableOfTypes {id:49992, int64Column:50, doubleColumn:31.582059, booleanColumn:False, dateColumn:1551-07-19, timestampColumn:1551-07-19 16:28:31, stringColumn:NULL})
+(0:49992:tableOfTypes {id:49992, int64Column:50, doubleColumn:31.582059, booleanColumn:False, dateColumn:1551-07-19, timestampColumn:1551-07-19 16:28:31, stringColumn:})
 
 -NAME FloatTest
 -QUERY MATCH (row:tableOfTypes) WHERE row.doubleColumn = 68.73718401556897 RETURN row.dateColumn;

test/test_files/demo_db/demo_db.test

@@ -39,7 +39,7 @@ Adam|Karissa
 Adam|Zhang
 Karissa|Zhang
 Zhang|Noura
-Noura|NULL
+Noura|
 
 -NAME OrderBy1
 -QUERY MATCH (u:User) RETURN u.name, u.age ORDER BY u.age;

test/test_files/tinysnb/agg/multi_label.test

@@ -13,7 +13,7 @@
 -NAME MultiLabelAggTest3
 -QUERY MATCH (a:person)-[e1:marries|:mixed|studyAt]->(b:person) RETURN e1.year, COUNT(*)
 ---- 8
-NULL|3
+|3
 1930|1
 1945|1
 2088|1
@@ -29,5 +29,5 @@ NULL|3
 20|2
 30|2
 45|3
-NULL|3
+|3
 

test/test_files/tinysnb/filter/multi_label.test

@@ -8,7 +8,7 @@
 -QUERY MATCH (a:person)-[e:mixed|:studyAt|:knows]->(b:person:organisation) WHERE e.year = 2088 RETURN a.ID, b.fName, b.orgCode
 -ENUMERATE
 ---- 1
-3|Elizabeth|NULL
+3|Elizabeth|
 
 -NAME MultiLabelTwoHopTest1
 -QUERY MATCH (a:person)<-[e:knows|:mixed|:meets]-(b:person)-[:knows|:mixed|:meets]->(c:person) WHERE b.ID = 7 AND a.ID = c.ID RETURN COUNT(*)

test/test_files/tinysnb/function/case.test

@@ -25,8 +25,8 @@ Hubert Blaine Wolfeschlegelsteinhausenbergerdorff
 -NAME CaseListTest
 -QUERY MATCH (a:person) WHERE a.ID > 6 RETURN CASE WHEN len(a.workedHours) = 1 THEN a.courseScoresPerTerm END
 ---- 4
-NULL
-NULL
+
+
 [[10]]
 [[6],[7],[8]]
 

test/test_files/tinysnb/match/multi_label.test

@@ -44,16 +44,16 @@
 -QUERY MATCH (a:person)-[e:mixed|:marries]->(b:person) RETURN a.ID, ID(e), e.note, e.year, b.ID
 -ENUMERATE
 ---- 10
-0|27|NULL|1930|2
-2|28|NULL|1945|5
-3|29|NULL|2088|7
-7|30|NULL|2066|3
-8|31|NULL|2120|3
-9|32|NULL|2022|3
-10|33|NULL|2020|2
-0|37|NULL|NULL|2
-3|38|long long long string|NULL|5
-7|39|short str|NULL|8
+0|27||1930|2
+2|28||1945|5
+3|29||2088|7
+7|30||2066|3
+8|31||2120|3
+9|32||2022|3
+10|33||2020|2
+0|37|||2
+3|38|long long long string||5
+7|39|short str||8
 
 -NAME MultiLabelOneHopTest5
 -QUERY MATCH (a:person)-[e:mixed|:studyAt|:knows]->(b:person:organisation) RETURN COUNT(*)

test/test_files/tinysnb/optional_match/optional_match.test

@@ -65,41 +65,41 @@
 ---- 3
 Elizabeth|Farooq
 Elizabeth|Greg
-Hubert Blaine Wolfeschlegelsteinhausenbergerdorff|NULL
+Hubert Blaine Wolfeschlegelsteinhausenbergerdorff|
 
 -NAME OptionalReturnTest
 -QUERY MATCH (a:person)-[:knows]->(b:person) WHERE a.fName='Alice' OPTIONAL MATCH (b)-[:studyAt]->(c:organisation) RETURN c.orgCode
 -ENUMERATE
 ---- 3
-NULL
-NULL
+
+
 325
 
 -NAME OptionalReturnTest2
 -QUERY MATCH (a:person) OPTIONAL MATCH (a)-[:knows]->(b:person) WHERE b.fName='Farooq' RETURN a.fName, b.fName
 -ENUMERATE
 ---- 8
-Alice|NULL
-Bob|NULL
-Carol|NULL
-Dan|NULL
+Alice|
+Bob|
+Carol|
+Dan|
 Elizabeth|Farooq
-Farooq|NULL
-Greg|NULL
-Hubert Blaine Wolfeschlegelsteinhausenbergerdorff|NULL
+Farooq|
+Greg|
+Hubert Blaine Wolfeschlegelsteinhausenbergerdorff|
 
 -NAME OptionalListExtendCountTest
 -QUERY MATCH (a:person) OPTIONAL MATCH (a)-[:studyAt]->(b:organisation) RETURN a.fName, b.name
 -ENUMERATE
 ---- 8
 Alice|ABFsUni
 Bob|ABFsUni
-Carol|NULL
-Dan|NULL
-Elizabeth|NULL
+Carol|
+Dan|
+Elizabeth|
 Farooq|ABFsUni
-Greg|NULL
-Hubert Blaine Wolfeschlegelsteinhausenbergerdorff|NULL
+Greg|
+Hubert Blaine Wolfeschlegelsteinhausenbergerdorff|
 
 -NAME OptionalListExtendTest2
 -QUERY MATCH (a:person) OPTIONAL MATCH (a)-[:knows]->(b:person)-[:knows]->(c:person) RETURN COUNT(*)

test/test_files/tinysnb/order_by/multi_label.test

@@ -25,13 +25,13 @@
 -QUERY MATCH (a:person:organisation)-[:mixed]->(b:person:organisation) return b.name, b.fName ORDER BY b.ID
 -ENUMERATE
 ---- 10
-NULL|Bob
-NULL|Bob
-NULL|Carol
-NULL|Carol
-NULL|Carol
-CsWork|NULL
-NULL|Dan
-DEsWork|NULL
-DEsWork|NULL
-NULL|Elizabeth
+|Bob
+|Bob
+|Carol
+|Carol
+|Carol
+CsWork|
+|Dan
+DEsWork|
+DEsWork|
+|Elizabeth