Fix #2158

src/binder/bind_expression/bind_function_expression.cpp

@@ -272,7 +272,36 @@ std::shared_ptr<Expression> ExpressionBinder::bindRecursiveJoinLengthFunction(
     if (expression.getDataType().getLogicalTypeID() != LogicalTypeID::RECURSIVE_REL) {
         return nullptr;
     }
-    return ((RelExpression&)expression).getLengthExpression();
+    if (expression.expressionType == common::PATH) {
+        int64_t numRels = 0u;
+        expression_vector recursiveRels;
+        for (auto& child : expression.getChildren()) {
+            if (ExpressionUtil::isRelVariable(*child)) {
+                numRels++;
+            } else if (ExpressionUtil::isRecursiveRelVariable(*child)) {
+                recursiveRels.push_back(child);
+            }
+        }
+        auto numRelsExpression = createLiteralExpression(std::make_unique<Value>(numRels));
+        if (recursiveRels.empty()) {
+            return numRelsExpression;
+        }
+        expression_vector children;
+        children.push_back(std::move(numRelsExpression));
+        children.push_back(
+            reinterpret_cast<RelExpression&>(*recursiveRels[0]).getLengthExpression());
+        auto result = bindScalarFunctionExpression(children, ADD_FUNC_NAME);
+        for (auto i = 1u; i < recursiveRels.size(); ++i) {
+            children[0] = std::move(result);
+            children[1] = reinterpret_cast<RelExpression&>(*recursiveRels[i]).getLengthExpression();
+            result = bindScalarFunctionExpression(children, ADD_FUNC_NAME);
+        }
+        return result;
+    } else if (ExpressionUtil::isRecursiveRelVariable(expression)) {
+        auto& recursiveRel = reinterpret_cast<const RelExpression&>(expression);
+        return recursiveRel.getLengthExpression();
+    }
+    return nullptr;
 }
 
 } // namespace binder

test/test_files/issue/issue.test

@@ -0,0 +1,20 @@
+-GROUP IssueTest
+-DATASET CSV empty
+
+--
+
+-CASE 2158
+
+-STATEMENT CREATE NODE TABLE N1(name STRING, PRIMARY KEY(name));
+---- ok
+-STATEMENT CREATE NODE TABLE N2(name STRING, PRIMARY KEY(name));
+---- ok
+-STATEMENT CREATE REL TABLE Rel1(FROM N1 TO N2);
+---- ok
+-STATEMENT CREATE REL TABLE Rel2(FROM N1 TO N2);
+---- ok
+-STATEMENT CREATE (n1:N1 {name: "n1a"}), (n2:N2 {name: "n2a"}), (n1)-[:Rel1]->(n2);
+---- ok
+-STATEMENT MATCH p = (n1:N1)-[:Rel1]->() return length(p);
+---- 1
+1

test/test_files/tinysnb/path/path.test

@@ -52,3 +52,44 @@
 [(0:0)-{_LABEL: knows, _ID: 3:2, date: 2021-06-30, meetTime: 2012-12-11 20:07:22, validInterval: 10 days, comments: [ioji232,jifhe8w99u43434]}->(0:3),(0:3)-{_LABEL: workAt, _ID: 5:1, year: 2010, grading: [2.100000,4.400000], rating: 7.600000}->(1:2)]
 [(0:0)-{_LABEL: marries, _ID: 7:0, usedAddress: [toronto], address: [4,5]}->(0:1),(0:1)-{_LABEL: studyAt, _ID: 4:1, year: 2020, places: [anew,jsdnwusklklklwewsd], length: 55, level: 120, code: 6689, temprature: 1, ulength: 90, ulevel: 220}->(1:0)]
 [(0:0)-{_LABEL: meets, _ID: 6:0, location: [7.820000,3.540000], times: 5, data: \xAA\xBB\xCC\xDD}->(0:1),(0:1)-{_LABEL: studyAt, _ID: 4:1, year: 2020, places: [anew,jsdnwusklklklwewsd], length: 55, level: 120, code: 6689, temprature: 1, ulength: 90, ulevel: 220}->(1:0)]
+
+-LOG PathLength
+-STATEMENT MATCH p = (a:person)-[e:knows]->(b:person) WHERE a.ID = 0 RETURN length(p), b.fName
+---- 3
+1|Bob
+1|Carol
+1|Dan
+-STATEMENT MATCH p = (a:person)-[e:knows*1..2]->(b:person) WHERE a.ID = 0 AND b.ID = 2 RETURN length(p), length(e)
+---- 3
+1|1
+2|2
+2|2
+-STATEMENT MATCH p = (a:person)-[e:knows*1..2]->(b:person)-[:knows]->(c:person) WHERE a.ID = 0 AND b.ID = 2 AND c.ID = 0 RETURN length(p), length(e)
+---- 3
+2|1
+3|2
+3|2
+-STATEMENT MATCH p = (a:person)-[e:knows*1..2]->(b:person)-[k:knows*1..2]->(c:person) WHERE a.ID = 0 AND b.ID = 2 AND c.ID = 0 RETURN length(p), length(e), length(k)
+---- 9
+2|1|1
+3|1|2
+3|1|2
+3|2|1
+3|2|1
+4|2|2
+4|2|2
+4|2|2
+4|2|2
+-STATEMENT MATCH p = (a:person)-[e:knows*1..2]->(b:person) RETURN length(a)
+---- error
+Binder exception: Cannot match a built-in function for given function LENGTH(NODE). Supported inputs are
+(STRING) -> INT64
+-STATEMENT MATCH p = (a:person)-[e:knows*1..2]->(b:person) RETURN len(p)
+---- error
+Binder exception: Cannot match a built-in function for given function LEN(RECURSIVE_REL). Supported inputs are
+(VAR_LIST) -> INT64
+(MAP) -> INT64
+-STATEMENT MATCH p = (a:person)-[e:knows]->(b:person) RETURN length(e)
+---- error
+Binder exception: Cannot match a built-in function for given function LENGTH(REL). Supported inputs are
+(STRING) -> INT64