[iotdb] branch master updated: [IOTDB-4246] Fix last query without data only return time column (#7146)

[hui]

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hui pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/iotdb.git


The following commit(s) were added to refs/heads/master by this push:
     new 210a0b532e [IOTDB-4246] Fix last query without data only return time 
column (#7146)
210a0b532e is described below

commit 210a0b532e0f703a07fa238e26c3134c7b0c4ea8
Author: Yifu Zhou <efuu1...@outlook.com>
AuthorDate: Mon Aug 29 16:13:29 2022 +0800

    [IOTDB-4246] Fix last query without data only return time column (#7146)
---
 .../org/apache/iotdb/db/it/query/IoTDBResultSetIT.java     | 14 ++++++++++++++
 .../apache/iotdb/db/mpp/plan/analyze/AnalyzeVisitor.java   |  3 +++
 2 files changed, 17 insertions(+)

diff --git 
a/integration-test/src/test/java/org/apache/iotdb/db/it/query/IoTDBResultSetIT.java
 
b/integration-test/src/test/java/org/apache/iotdb/db/it/query/IoTDBResultSetIT.java
index 8f2db6c50d..2e78747693 100644
--- 
a/integration-test/src/test/java/org/apache/iotdb/db/it/query/IoTDBResultSetIT.java
+++ 
b/integration-test/src/test/java/org/apache/iotdb/db/it/query/IoTDBResultSetIT.java
@@ -183,4 +183,18 @@ public class IoTDBResultSetIT {
         ColumnHeaderConstant.COLUMN_DEVICES + "," + 
ColumnHeaderConstant.COLUMN_IS_ALIGNED + ",";
     resultSetEqualTest("show devices root.sg1.**", expectedHeader, 
emptyResultSet);
   }
+
+  @Test
+  public void emptyLastQueryTest() {
+    String expectedHeader =
+        ColumnHeaderConstant.COLUMN_TIME
+            + ","
+            + ColumnHeaderConstant.COLUMN_TIMESERIES
+            + ","
+            + ColumnHeaderConstant.COLUMN_VALUE
+            + ","
+            + ColumnHeaderConstant.COLUMN_TIMESERIES_DATATYPE
+            + ",";
+    resultSetEqualTest("select last s1 from root.sg.d1", expectedHeader, 
emptyResultSet);
+  }
 }
diff --git 
a/server/src/main/java/org/apache/iotdb/db/mpp/plan/analyze/AnalyzeVisitor.java 
b/server/src/main/java/org/apache/iotdb/db/mpp/plan/analyze/AnalyzeVisitor.java
index 8b6cc9bc98..8d271db790 100644
--- 
a/server/src/main/java/org/apache/iotdb/db/mpp/plan/analyze/AnalyzeVisitor.java
+++ 
b/server/src/main/java/org/apache/iotdb/db/mpp/plan/analyze/AnalyzeVisitor.java
@@ -179,6 +179,9 @@ public class AnalyzeVisitor extends 
StatementVisitor<Analysis, MPPQueryContext>
       logger.info("{} fetch schema done", getLogHeader());
       // If there is no leaf node in the schema tree, the query should be 
completed immediately
       if (schemaTree.isEmpty()) {
+        if (queryStatement.isLastQuery()) {
+          
analysis.setRespDatasetHeader(DatasetHeaderFactory.getLastQueryHeader());
+        }
         analysis.setFinishQueryAfterAnalyze(true);
         return analysis;
       }