Check variable existence and modify doc. (#1151)

vesoft-inc · Nov 19, 2019 · e4b8af7 · e4b8af7
1 parent 1ae90bb
commit e4b8af7
Show file tree

Hide file tree

Showing 4 changed files with 15 additions and 13 deletions.
diff --git a/...age/4.statement-syntax/2.data-query-and-manipulation-statements/fetch-syntax.md b/...age/4.statement-syntax/2.data-query-and-manipulation-statements/fetch-syntax.md
@@ -27,7 +27,7 @@ nebula> FETCH PROP ON player 1 YIELD player.name, player.age
 nebula> FETCH PROP ON player hash(\"nebula\")  YIELD player.name, player.age
 -- 沿边 e1 寻找节点 1 的所有近邻，返回其姓名和年龄属性
 nebula> GO FROM 1 over e1 YIELD e1._dst AS id | FETCH PROP ON player $-.id YIELD player.name, player.age
--- 与上述语句相同
+-- 与上述语法相同
 nebula> $var = GO FROM 1 over e1 YIELD e1._dst AS id; FETCH PROP ON player $var.id YIELD player.name, player.age
 -- 获取 1，2，3 三个节点，返回姓名和年龄都不相同的记录
 nebula> FETCH PROP ON player 1,2,3 YIELD DISTINCT player.name, player.age

diff --git a/...age/4.statement-syntax/2.data-query-and-manipulation-statements/fetch-syntax.md b/...age/4.statement-syntax/2.data-query-and-manipulation-statements/fetch-syntax.md
@@ -4,7 +4,7 @@ The `FETCH` syntax is used to get vertex/edge's properties.
 
 ## Fetch Vertex property
 
-Use `FETCH PROP ON` to return a (list of) vertex's properties. Currently, you can get multiple vertices' properties with the same tag in one sentence.  
+Use `FETCH PROP ON` to return a (list of) vertex's properties. Currently, you can get multiple vertices' properties with the same tag in one sentence.
 
 ```ngql
 FETCH PROP ON <tag_name> <vertex_id_list> [YIELD [DISTINCT] <return_list>]

diff --git a/src/graph/FetchEdgesExecutor.cpp b/src/graph/FetchEdgesExecutor.cpp
@@ -143,16 +143,17 @@ Status FetchEdgesExecutor::setupEdgeKeysFromRef() {
     const InterimResult *inputs;
     if (sentence_->ref()->isInputExpr()) {
         inputs = inputs_.get();
-        if (inputs == nullptr || !inputs->hasData()) {
-            // we have empty imputs from pipe.
-            return Status::OK();
-        }
     } else {
-        inputs = ectx()->variableHolder()->get(varname_);
-        if (inputs == nullptr || !inputs->hasData()) {
+        bool existing = false;
+        inputs = ectx()->variableHolder()->get(varname_, &existing);
+        if (!existing) {
             return Status::Error("Variable `%s' not defined", varname_.c_str());
         }
     }
+    if (inputs == nullptr || !inputs->hasData()) {
+        // we have empty imputs from pipe.
+        return Status::OK();
+    }
 
     auto ret = inputs->getVIDs(*srcid_);
     if (!ret.ok()) {

diff --git a/src/graph/FetchVerticesExecutor.cpp b/src/graph/FetchVerticesExecutor.cpp
@@ -286,15 +286,16 @@ Status FetchVerticesExecutor::setupVidsFromRef() {
     const InterimResult *inputs;
     if (varname_ == nullptr) {
         inputs = inputs_.get();
-        if (inputs == nullptr || !inputs->hasData()) {
-            return Status::OK();
-        }
     } else {
-        inputs = ectx()->variableHolder()->get(*varname_);
-        if (inputs == nullptr || !inputs->hasData()) {
+        bool existing = false;
+        inputs = ectx()->variableHolder()->get(*varname_, &existing);
+        if (!existing) {
             return Status::Error("Variable `%s' not defined", varname_->c_str());
         }
     }
+    if (inputs == nullptr || !inputs->hasData()) {
+        return Status::OK();
+    }
 
     StatusOr<std::vector<VertexID>> result;
     if (distinct_) {