Fix yield (#546)

* Fix yield.

* Add test.

* Set var for tail.

* Add more yield test.

* Skip update minloglevel test.

src/executor/query/ProjectExecutor.cpp

@@ -26,7 +26,6 @@ folly::Future<Status> ProjectExecutor::execute() {
     DataSet ds;
     ds.colNames = project->colNames();
     for (; iter->valid(); iter->next()) {
-        VLOG(1) << "row: " << *iter->row();
         Row row;
         for (auto& col : columns) {
             Value val = col->expr()->eval(ctx(iter.get()));

src/validator/YieldValidator.cpp

@@ -48,11 +48,15 @@ Status YieldValidator::validateImpl() {
         NG_RETURN_IF_ERROR(checkAggFunAndBuildGroupItems(yield->yield()));
     }
 
-    if (exprProps_.inputProps().empty() && exprProps_.varProps().empty()) {
+    if (exprProps_.inputProps().empty() && exprProps_.varProps().empty() && inputVarName_.empty()) {
         // generate constant expression result into querycontext
         genConstantExprValues();
     }
 
+    if (!exprProps_.varProps().empty() && !userDefinedVarNameList_.empty()) {
+        userDefinedVarName_ = *userDefinedVarNameList_.begin();
+    }
+
     return Status::OK();
 }
 
@@ -187,6 +191,13 @@ Status YieldValidator::validateWhere(const WhereClause *clause) {
 Status YieldValidator::toPlan() {
     auto yield = static_cast<const YieldSentence *>(sentence_);
 
+    std::string inputVar;
+    if (!userDefinedVarName_.empty()) {
+        inputVar = userDefinedVarName_;
+    } else if (!constantExprVar_.empty()) {
+        inputVar = constantExprVar_;
+    }
+
     Filter *filter = nullptr;
     if (yield->where()) {
         filter = Filter::make(qctx_, nullptr, filterCondition_);
@@ -194,9 +205,6 @@ Status YieldValidator::toPlan() {
         std::transform(
             inputs_.cbegin(), inputs_.cend(), colNames.begin(), [](auto &col) { return col.name; });
         filter->setColNames(std::move(colNames));
-        if (!constantExprVar_.empty()) {
-            filter->setInputVar(constantExprVar_);
-        }
     }
 
     SingleInputNode *dedupDep = nullptr;
@@ -206,6 +214,9 @@ Status YieldValidator::toPlan() {
         // We do not use group items later, so move it is safe
         dedupDep = Aggregate::make(qctx_, filter, {}, std::move(groupItems_));
     }
+    if (filter == nullptr && !inputVar.empty()) {
+        dedupDep->setInputVar(inputVar);
+    }
 
     dedupDep->setColNames(std::move(outputColumnNames_));
     if (filter != nullptr) {
@@ -215,10 +226,9 @@ Status YieldValidator::toPlan() {
         tail_ = dedupDep;
     }
 
-    if (!exprProps_.varProps().empty()) {
-        DCHECK_EQ(exprProps_.varProps().size(), 1u);
-        auto var = exprProps_.varProps().cbegin()->first;
-        static_cast<SingleInputNode *>(tail_)->setInputVar(var);
+    // Otherwise the input of tail_ would be set by pipe.
+    if (!inputVar.empty()) {
+        static_cast<SingleInputNode *>(tail_)->setInputVar(inputVar);
     }
 
     if (yield->yield()->isDistinct()) {

src/validator/YieldValidator.h

@@ -47,6 +47,7 @@ private:
     std::vector<std::string> outputColumnNames_;
     std::vector<Aggregate::GroupItem> groupItems_;
     std::string constantExprVar_;
+    std::string userDefinedVarName_;
     Expression *filterCondition_{nullptr};
 };
 

tests/admin/test_configs.py

@@ -5,6 +5,7 @@
 # This source code is licensed under Apache 2.0 License,
 # attached with Common Clause Condition 1.0, found in the LICENSES directory.
 
+import pytest
 from tests.common.nebula_test_suite import NebulaTestSuite
 
 
@@ -79,6 +80,24 @@ class TestConfigs(NebulaTestSuite):
                            ['STORAGE', 'rocksdb_block_based_table_options', 'map', 'MUTABLE', {"block_size":"8192"}]]
         self.check_out_of_order_result(resp, expected_result)
 
+        # update rocksdb
+        resp = self.client.execute('''
+                                   UPDATE CONFIGS storage:rocksdb_column_family_options={
+                                   max_bytes_for_level_base=1024,
+                                   write_buffer_size=1024,
+                                   max_write_buffer_number=4}
+                                   ''')
+        self.check_resp_succeeded(resp)
+
+        # get result
+        resp = self.client.execute('GET CONFIGS storage:rocksdb_column_family_options')
+        self.check_resp_succeeded(resp)
+        value = {"max_bytes_for_level_base": 1024, "write_buffer_size": 1024, "max_write_buffer_number": 4}
+        expected_result = [['STORAGE', 'rocksdb_column_family_options', 'map', 'MUTABLE', value]]
+        self.check_result(resp, expected_result)
+
+    @pytest.mark.skip("The change of minloglevel will infulence the whole test.")
+    def test_update_configs(self):
         # set and get a config of all module
         resp = self.client.execute('UPDATE CONFIGS minloglevel={}'.format(2))
         self.check_resp_succeeded(resp)
@@ -101,18 +120,4 @@ class TestConfigs(NebulaTestSuite):
                            ['STORAGE', 'minloglevel', 'int', 'MUTABLE', 3]]
         self.check_result(resp, expected_result)
 
-        # update rocksdb
-        resp = self.client.execute('''
-                                   UPDATE CONFIGS storage:rocksdb_column_family_options={
-                                   max_bytes_for_level_base=1024,
-                                   write_buffer_size=1024,
-                                   max_write_buffer_number=4}
-                                   ''')
-        self.check_resp_succeeded(resp)
 
-        # get result
-        resp = self.client.execute('GET CONFIGS storage:rocksdb_column_family_options')
-        self.check_resp_succeeded(resp)
-        value = {"max_bytes_for_level_base": 1024, "write_buffer_size": 1024, "max_write_buffer_number": 4}
-        expected_result = [['STORAGE', 'rocksdb_column_family_options', 'map', 'MUTABLE', value]]
-        self.check_result(resp, expected_result)

tests/tck/features/bugfix/TestYieldConstantAfterPipe.feature

+# Copyright (c) 2020 vesoft inc. All rights reserved.
+#
+# This source code is licensed under Apache 2.0 License,
+# attached with Common Clause Condition 1.0, found in the LICENSES directory.
+Feature: Test yield constant after pipe
+
+  Background:
+    Given a graph with space named "nba"
+
+  Scenario: yield constant after pipe
+    When executing query:
+      """
+      GO FROM "Tim Duncan" OVER * | YIELD 1 AS a;
+      """
+    Then the result should be, in any order:
+      | a |
+      | 1 |
+      | 1 |
+      | 1 |
+      | 1 |
+      | 1 |
+      | 1 |
+      | 1 |
+    When executing query:
+      """
+      GO FROM "Tim Duncan" OVER * | YIELD 1 AS a WHERE true;
+      """
+    Then the result should be, in any order:
+      | a |
+      | 1 |
+      | 1 |
+      | 1 |
+      | 1 |
+      | 1 |
+      | 1 |
+      | 1 |
+    When executing query:
+      """
+      GO FROM "Tim Duncan" OVER * | YIELD 1 AS a WHERE false;
+      """
+    Then the result should be, in any order:
+      | a |