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Posted to commits@iotdb.apache.org by ja...@apache.org on 2020/04/29 08:20:48 UTC

[incubator-iotdb] 01/01: Add a jdbc-like way to fetch data in session

This is an automated email from the ASF dual-hosted git repository.

jackietien pushed a commit to branch SessionNext
in repository https://gitbox.apache.org/repos/asf/incubator-iotdb.git

commit 81a8166e81899eaaf8781cb9bef248cf5bf12bd8
Author: JackieTien97 <Ja...@foxmail.com>
AuthorDate: Wed Apr 29 16:20:24 2020 +0800

    Add a jdbc-like way to fetch data in session
---
 .../main/java/org/apache/iotdb/SessionExample.java |  50 ++--
 .../java/org/apache/iotdb/session/Session.java     |   2 +-
 .../org/apache/iotdb/session/SessionDataSet.java   | 326 +++++++++++++++++++--
 .../iotdb/session/IoTDBSessionIteratorIT.java      | 122 ++++++++
 4 files changed, 458 insertions(+), 42 deletions(-)

diff --git a/example/session/src/main/java/org/apache/iotdb/SessionExample.java b/example/session/src/main/java/org/apache/iotdb/SessionExample.java
index 6aa0e25..03310d0 100644
--- a/example/session/src/main/java/org/apache/iotdb/SessionExample.java
+++ b/example/session/src/main/java/org/apache/iotdb/SessionExample.java
@@ -18,21 +18,21 @@
  */
 package org.apache.iotdb;
 
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 import org.apache.iotdb.rpc.BatchExecutionException;
 import org.apache.iotdb.rpc.IoTDBConnectionException;
 import org.apache.iotdb.rpc.StatementExecutionException;
 import org.apache.iotdb.session.Session;
 import org.apache.iotdb.session.SessionDataSet;
+import org.apache.iotdb.session.SessionDataSet.DataIterator;
 import org.apache.iotdb.tsfile.file.metadata.enums.CompressionType;
 import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
 import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding;
 import org.apache.iotdb.tsfile.write.record.Tablet;
 import org.apache.iotdb.tsfile.write.schema.MeasurementSchema;
-import org.apache.iotdb.tsfile.write.schema.Schema;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
 
 public class SessionExample {
 
@@ -49,7 +49,6 @@ public class SessionExample {
       if (!e.getMessage().contains("StorageGroupAlreadySetException")) {
         throw e;
       }
-//       ignore duplicated set
     }
 
     createTimeseries();
@@ -60,6 +59,7 @@ public class SessionExample {
     insertRecords();
     nonQuery();
     query();
+    queryByIterator();
     deleteData();
     deleteTimeseries();
     session.close();
@@ -95,7 +95,8 @@ public class SessionExample {
   private static void createMultiTimeseries()
       throws IoTDBConnectionException, BatchExecutionException {
 
-    if (!session.checkTimeseriesExists("root.sg1.d2.s1") && !session.checkTimeseriesExists("root.sg1.d2.s2")) {
+    if (!session.checkTimeseriesExists("root.sg1.d2.s1") && !session
+        .checkTimeseriesExists("root.sg1.d2.s2")) {
       List<String> paths = new ArrayList<>();
       paths.add("root.sg1.d2.s1");
       paths.add("root.sg1.d2.s2");
@@ -126,8 +127,9 @@ public class SessionExample {
       alias.add("weight1");
       alias.add("weight2");
 
-      session.createMultiTimeseries(paths, tsDataTypes, tsEncodings, compressionTypes, null, tagsList,
-          attributesList, alias);
+      session
+          .createMultiTimeseries(paths, tsDataTypes, tsEncodings, compressionTypes, null, tagsList,
+              attributesList, alias);
     }
   }
 
@@ -193,15 +195,11 @@ public class SessionExample {
 
   /**
    * insert the data of a device. For each timestamp, the number of measurements is the same.
-   *
+   * <p>
    * a Tablet example:
-   *
-   *      device1
-   * time s1, s2, s3
-   * 1,   1,  1,  1
-   * 2,   2,  2,  2
-   * 3,   3,  3,  3
-   *
+   * <p>
+   * device1 time s1, s2, s3 1,   1,  1,  1 2,   2,  2,  2 3,   3,  3,  3
+   * <p>
    * Users need to control the count of Tablet and write a batch when it reaches the maxBatchSize
    */
   private static void insertTablet() throws IoTDBConnectionException, BatchExecutionException {
@@ -245,7 +243,7 @@ public class SessionExample {
     Tablet tablet1 = new Tablet("root.sg1.d1", schemaList, 100);
     Tablet tablet2 = new Tablet("root.sg1.d2", schemaList, 100);
     Tablet tablet3 = new Tablet("root.sg1.d3", schemaList, 100);
-    
+
     Map<String, Tablet> tabletMap = new HashMap<>();
     tabletMap.put("root.sg1.d1", tablet1);
     tabletMap.put("root.sg1.d2", tablet2);
@@ -317,6 +315,22 @@ public class SessionExample {
     dataSet.closeOperationHandle();
   }
 
+  private static void queryByIterator()
+      throws IoTDBConnectionException, StatementExecutionException {
+    SessionDataSet dataSet;
+    dataSet = session.executeQueryStatement("select * from root.sg1.d1");
+    DataIterator iterator = dataSet.iterator();
+    System.out.println(dataSet.getColumnNames());
+    dataSet.setBatchSize(1024); // default is 512
+    while (iterator.next()) {
+      System.out.println(String.format("%s,%s,%s,%s,%s", iterator.getLong(1), iterator.getLong(2),
+          iterator.getLong("root.sg1.d1.s2"), iterator.getLong(4),
+          iterator.getObject("root.sg1.d1.s4")));
+    }
+
+    dataSet.closeOperationHandle();
+  }
+
   private static void nonQuery() throws IoTDBConnectionException, StatementExecutionException {
     session.executeNonQueryStatement("insert into root.sg1.d1(timestamp,s1) values(200, 1);");
   }
diff --git a/session/src/main/java/org/apache/iotdb/session/Session.java b/session/src/main/java/org/apache/iotdb/session/Session.java
index 0407093..15635e5 100644
--- a/session/src/main/java/org/apache/iotdb/session/Session.java
+++ b/session/src/main/java/org/apache/iotdb/session/Session.java
@@ -651,7 +651,7 @@ public class Session {
     }
 
     RpcUtils.verifySuccess(execResp.getStatus());
-    return new SessionDataSet(sql, execResp.getColumns(), execResp.getDataTypeList(),
+    return new SessionDataSet(sql, execResp.getColumns(), execResp.getDataTypeList(), execResp.columnNameIndexMap,
         execResp.getQueryId(), client, sessionId, execResp.queryDataSet);
   }
 
diff --git a/session/src/main/java/org/apache/iotdb/session/SessionDataSet.java b/session/src/main/java/org/apache/iotdb/session/SessionDataSet.java
index 763922d..fdfaf1a 100644
--- a/session/src/main/java/org/apache/iotdb/session/SessionDataSet.java
+++ b/session/src/main/java/org/apache/iotdb/session/SessionDataSet.java
@@ -19,11 +19,12 @@
 package org.apache.iotdb.session;
 
 import java.nio.ByteBuffer;
-import java.sql.SQLException;
+import java.sql.Timestamp;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import org.apache.iotdb.rpc.IoTDBConnectionException;
 import org.apache.iotdb.rpc.RpcUtils;
 import org.apache.iotdb.rpc.StatementExecutionException;
@@ -39,10 +40,15 @@ import org.apache.iotdb.tsfile.read.common.Field;
 import org.apache.iotdb.tsfile.read.common.RowRecord;
 import org.apache.iotdb.tsfile.utils.Binary;
 import org.apache.iotdb.tsfile.utils.BytesUtils;
+import org.apache.iotdb.tsfile.utils.ReadWriteIOUtils;
 import org.apache.thrift.TException;
 
 public class SessionDataSet {
 
+  private static final String TIMESTAMP_STR = "Time";
+  private static final int START_INDEX = 2;
+  private static final String VALUE_IS_NULL = "The value got by %s (column name) is NULL.";
+
   private boolean hasCachedRecord = false;
   private String sql;
   private long queryId;
@@ -50,11 +56,9 @@ public class SessionDataSet {
   private TSIService.Iface client;
   private int batchSize = 1024;
   private List<String> columnNameList;
-  private List<String> columnTypeDeduplicatedList;
-  // duplicated column index -> origin index
-  Map<Integer, Integer> duplicateLocation;
+  protected List<TSDataType> columnTypeDeduplicatedList; // deduplicated from columnTypeList
   // column name -> column location
-  Map<String, Integer> columnMap;
+  Map<String, Integer> columnOrdinalMap;
   // column size
   int columnSize = 0;
 
@@ -65,8 +69,11 @@ public class SessionDataSet {
   private byte[] currentBitmap; // used to cache the current bitmap for every column
   private static final int flag = 0x80; // used to do `or` operation with bitmap to judge whether the value is null
 
+  private byte[] time; // used to cache the current time value
+  private byte[][] values; // used to cache the current row record value
+
 
-  public SessionDataSet(String sql, List<String> columnNameList, List<String> columnTypeList,
+  public SessionDataSet(String sql, List<String> columnNameList, List<String> columnTypeList, Map<String, Integer> columnNameIndex,
       long queryId, TSIService.Iface client, long sessionId, TSQueryDataSet queryDataSet) {
     this.sessionId = sessionId;
     this.sql = sql;
@@ -76,22 +83,42 @@ public class SessionDataSet {
     currentBitmap = new byte[columnNameList.size()];
     columnSize = columnNameList.size();
 
-    // deduplicate columnTypeList according to columnNameList
-    this.columnTypeDeduplicatedList = new ArrayList<>();
-    // duplicated column index -> origin index
-    duplicateLocation = new HashMap<>();
-    // column name -> column location
-    columnMap = new HashMap<>();
-    for (int i = 0; i < columnNameList.size(); i++) {
-      String name = columnNameList.get(i);
-      if (columnMap.containsKey(name)) {
-        duplicateLocation.put(i, columnMap.get(name));
-      } else {
-        columnMap.put(name, i);
-        columnTypeDeduplicatedList.add(columnTypeList.get(i));
+    this.columnNameList = new ArrayList<>();
+    this.columnNameList.add(TIMESTAMP_STR);
+    // deduplicate and map
+    this.columnOrdinalMap = new HashMap<>();
+    this.columnOrdinalMap.put(TIMESTAMP_STR, 1);
+
+    // deduplicate and map
+    if (columnNameIndex != null) {
+      this.columnTypeDeduplicatedList = new ArrayList<>(columnNameIndex.size());
+      for (int i = 0; i < columnNameIndex.size(); i++) {
+        columnTypeDeduplicatedList.add(null);
+      }
+      for (int i = 0; i < columnNameList.size(); i++) {
+        String name = columnNameList.get(i);
+        this.columnNameList.add(name);
+        if (!columnOrdinalMap.containsKey(name)) {
+          int index = columnNameIndex.get(name);
+          columnOrdinalMap.put(name, index+START_INDEX);
+          columnTypeDeduplicatedList.set(index, TSDataType.valueOf(columnTypeList.get(i)));
+        }
+      }
+    } else {
+      this.columnTypeDeduplicatedList = new ArrayList<>();
+      int index = START_INDEX;
+      for (int i = 0; i < columnNameList.size(); i++) {
+        String name = columnNameList.get(i);
+        this.columnNameList.add(name);
+        if (!columnOrdinalMap.containsKey(name)) {
+          columnOrdinalMap.put(name, index++);
+          columnTypeDeduplicatedList.add(TSDataType.valueOf(columnTypeList.get(i)));
+        }
       }
     }
 
+    time = new byte[Long.BYTES];
+    values = new byte[columnNameList.size()][];
     this.tsQueryDataSet = queryDataSet;
   }
 
@@ -142,9 +169,9 @@ public class SessionDataSet {
     int loc = 0;
     for (int i = 0; i < columnSize; i++) {
       Field field;
-
-      if (duplicateLocation.containsKey(i)) {
-        field = Field.copy(outFields.get(duplicateLocation.get(i)));
+      int deduplicatedIndex = columnOrdinalMap.get(columnNameList.get(i+1)) - START_INDEX;
+      if (deduplicatedIndex < i) {
+        field = Field.copy(outFields.get(deduplicatedIndex));
       } else {
         ByteBuffer bitmapBuffer = tsQueryDataSet.bitmapList.get(loc);
         // another new 8 row, should move the bitmap buffer position to next byte
@@ -154,7 +181,7 @@ public class SessionDataSet {
 
         if (!isNull(loc, rowsIndex)) {
           ByteBuffer valueBuffer = tsQueryDataSet.valueList.get(loc);
-          TSDataType dataType = TSDataType.valueOf(columnTypeDeduplicatedList.get(loc));
+          TSDataType dataType = columnTypeDeduplicatedList.get(loc);
           field = new Field(dataType);
           switch (dataType) {
             case BOOLEAN:
@@ -232,4 +259,257 @@ public class SessionDataSet {
           "Error occurs when connecting to server for close operation, because: " + e, e);
     }
   }
+
+  public DataIterator iterator() {
+    return new DataIterator();
+  }
+
+  public class DataIterator {
+
+    private boolean emptyResultSet = false;
+
+    public boolean next() throws StatementExecutionException {
+      if (hasCachedResults()) {
+        constructOneRow();
+        return true;
+      }
+      if (emptyResultSet) {
+        return false;
+      }
+      if (fetchResults()) {
+        constructOneRow();
+        return true;
+      }
+      return false;
+    }
+
+    private boolean fetchResults() throws StatementExecutionException {
+      rowsIndex = 0;
+      TSFetchResultsReq req = new TSFetchResultsReq(sessionId, sql, batchSize, queryId, true);
+      try {
+        TSFetchResultsResp resp = client.fetchResults(req);
+
+        RpcUtils.verifySuccess(resp.getStatus());
+        if (!resp.hasResultSet) {
+          emptyResultSet = true;
+        } else {
+          tsQueryDataSet = resp.getQueryDataSet();
+        }
+        return resp.hasResultSet;
+      } catch (TException e) {
+        throw new StatementExecutionException(
+            "Cannot fetch result from server, because of network connection: {} ", e);
+      }
+    }
+
+    private void constructOneRow() {
+      tsQueryDataSet.time.get(time);
+      for (int i = 0; i < tsQueryDataSet.bitmapList.size(); i++) {
+        ByteBuffer bitmapBuffer = tsQueryDataSet.bitmapList.get(i);
+        // another new 8 row, should move the bitmap buffer position to next byte
+        if (rowsIndex % 8 == 0) {
+          currentBitmap[i] = bitmapBuffer.get();
+        }
+        values[i] = null;
+        if (!isNull(i, rowsIndex)) {
+          ByteBuffer valueBuffer = tsQueryDataSet.valueList.get(i);
+          TSDataType dataType = columnTypeDeduplicatedList.get(i);
+          switch (dataType) {
+            case BOOLEAN:
+              if (values[i] == null) {
+                values[i] = new byte[1];
+              }
+              valueBuffer.get(values[i]);
+              break;
+            case INT32:
+              if (values[i] == null) {
+                values[i] = new byte[Integer.BYTES];
+              }
+              valueBuffer.get(values[i]);
+              break;
+            case INT64:
+              if (values[i] == null) {
+                values[i] = new byte[Long.BYTES];
+              }
+              valueBuffer.get(values[i]);
+              break;
+            case FLOAT:
+              if (values[i] == null) {
+                values[i] = new byte[Float.BYTES];
+              }
+              valueBuffer.get(values[i]);
+              break;
+            case DOUBLE:
+              if (values[i] == null) {
+                values[i] = new byte[Double.BYTES];
+              }
+              valueBuffer.get(values[i]);
+              break;
+            case TEXT:
+              int length = valueBuffer.getInt();
+              values[i] = ReadWriteIOUtils.readBytes(valueBuffer, length);
+              break;
+            default:
+              throw new UnSupportedDataTypeException(
+                  String.format("Data type %s is not supported.", columnTypeDeduplicatedList.get(i)));
+          }
+        }
+      }
+      rowsIndex++;
+    }
+
+    private boolean hasCachedResults() {
+      return (tsQueryDataSet != null && tsQueryDataSet.time.hasRemaining());
+    }
+
+    public boolean getBoolean(int columnIndex) throws StatementExecutionException {
+      return getBoolean(findColumnNameByIndex(columnIndex));
+    }
+
+    public boolean getBoolean(String columnName) throws StatementExecutionException {
+      checkRecord();
+      int index = columnOrdinalMap.get(columnName) - START_INDEX;
+      if (values[index] != null) {
+        return BytesUtils.bytesToBool(values[index]);
+      }
+      else {
+        throw new StatementExecutionException(String.format(VALUE_IS_NULL, columnName));
+      }
+    }
+
+    public double getDouble(int columnIndex) throws StatementExecutionException {
+      return getDouble(findColumnNameByIndex(columnIndex));
+    }
+
+    public double getDouble(String columnName) throws StatementExecutionException {
+      checkRecord();
+      int index = columnOrdinalMap.get(columnName) - START_INDEX;
+      if (values[index] != null) {
+        return BytesUtils.bytesToDouble(values[index]);
+      } else {
+        throw new StatementExecutionException(String.format(VALUE_IS_NULL, columnName));
+      }
+    }
+
+    public float getFloat(int columnIndex) throws StatementExecutionException {
+      return getFloat(findColumnNameByIndex(columnIndex));
+    }
+
+    public float getFloat(String columnName) throws StatementExecutionException {
+      checkRecord();
+      int index = columnOrdinalMap.get(columnName) - START_INDEX;
+      if (values[index] != null) {
+        return BytesUtils.bytesToFloat(values[index]);
+      } else {
+        throw new StatementExecutionException(String.format(VALUE_IS_NULL, columnName));
+      }
+    }
+
+    public int getInt(int columnIndex) throws StatementExecutionException {
+      return getInt(findColumnNameByIndex(columnIndex));
+    }
+
+    public int getInt(String columnName) throws StatementExecutionException {
+      checkRecord();
+      int index = columnOrdinalMap.get(columnName) - START_INDEX;
+      if (values[index] != null) {
+        return BytesUtils.bytesToInt(values[index]);
+      } else {
+        throw new StatementExecutionException(String.format(VALUE_IS_NULL, columnName));
+      }
+    }
+
+    public long getLong(int columnIndex) throws StatementExecutionException {
+      return getLong(findColumnNameByIndex(columnIndex));
+    }
+
+    public long getLong(String columnName) throws StatementExecutionException {
+      checkRecord();
+      if (columnName.equals(TIMESTAMP_STR)) {
+        return BytesUtils.bytesToLong(time);
+      }
+      int index = columnOrdinalMap.get(columnName) - START_INDEX;
+      if (values[index] != null) {
+        return BytesUtils.bytesToLong(values[index]);
+      } else {
+        throw new StatementExecutionException(String.format(VALUE_IS_NULL, columnName));
+      }
+    }
+
+    public Object getObject(int columnIndex) throws StatementExecutionException {
+      return getObject(findColumnNameByIndex(columnIndex));
+    }
+
+    public Object getObject(String columnName) throws StatementExecutionException {
+      return getValueByName(columnName);
+    }
+
+    public String getString(int columnIndex) throws StatementExecutionException {
+      return getString(findColumnNameByIndex(columnIndex));
+    }
+
+    public String getString(String columnName) throws StatementExecutionException {
+      return getValueByName(columnName);
+    }
+
+    public Timestamp getTimestamp(int columnIndex) throws StatementExecutionException {
+      return new Timestamp(getLong(columnIndex));
+    }
+
+    public Timestamp getTimestamp(String columnName) throws StatementExecutionException {
+      return getTimestamp(findColumn(columnName));
+    }
+
+    public int findColumn(String columnName) {
+      return columnOrdinalMap.get(columnName);
+    }
+
+    private String getValueByName(String columnName) throws StatementExecutionException {
+      checkRecord();
+      if (columnName.equals(TIMESTAMP_STR)) {
+        return String.valueOf(BytesUtils.bytesToLong(time));
+      }
+      int index = columnOrdinalMap.get(columnName) - START_INDEX;
+      if (index < 0 || index >= values.length || values[index] == null) {
+        return null;
+      }
+      return getString(index, columnTypeDeduplicatedList.get(index), values);
+    }
+
+    protected String getString(int index, TSDataType tsDataType, byte[][] values) {
+      switch (tsDataType) {
+        case BOOLEAN:
+          return String.valueOf(BytesUtils.bytesToBool(values[index]));
+        case INT32:
+          return String.valueOf(BytesUtils.bytesToInt(values[index]));
+        case INT64:
+          return String.valueOf(BytesUtils.bytesToLong(values[index]));
+        case FLOAT:
+          return String.valueOf(BytesUtils.bytesToFloat(values[index]));
+        case DOUBLE:
+          return String.valueOf(BytesUtils.bytesToDouble(values[index]));
+        case TEXT:
+          return new String(values[index]);
+        default:
+          return null;
+      }
+    }
+
+    private void checkRecord() throws StatementExecutionException {
+      if (Objects.isNull(tsQueryDataSet)) {
+        throw new StatementExecutionException("No record remains");
+      }
+    }
+  }
+
+  private String findColumnNameByIndex(int columnIndex) throws StatementExecutionException {
+    if (columnIndex <= 0) {
+      throw new StatementExecutionException("column index should start from 1");
+    }
+    if (columnIndex > columnNameList.size()) {
+      throw new StatementExecutionException(
+          String.format("column index %d out of range %d", columnIndex, columnNameList.size()));
+    }
+    return columnNameList.get(columnIndex - 1);
+  }
 }
diff --git a/session/src/test/java/org/apache/iotdb/session/IoTDBSessionIteratorIT.java b/session/src/test/java/org/apache/iotdb/session/IoTDBSessionIteratorIT.java
new file mode 100644
index 0000000..8d6ec3e
--- /dev/null
+++ b/session/src/test/java/org/apache/iotdb/session/IoTDBSessionIteratorIT.java
@@ -0,0 +1,122 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.iotdb.session;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import java.util.ArrayList;
+import java.util.List;
+import org.apache.iotdb.db.conf.IoTDBConstant;
+import org.apache.iotdb.db.utils.EnvironmentUtils;
+import org.apache.iotdb.rpc.IoTDBConnectionException;
+import org.apache.iotdb.rpc.StatementExecutionException;
+import org.apache.iotdb.session.SessionDataSet.DataIterator;
+import org.apache.iotdb.tsfile.file.metadata.enums.CompressionType;
+import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
+import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class IoTDBSessionIteratorIT {
+
+  private Session session;
+
+  @Before
+  public void setUp() throws Exception {
+    System.setProperty(IoTDBConstant.IOTDB_CONF, "src/test/resources/");
+    EnvironmentUtils.closeStatMonitor();
+    EnvironmentUtils.envSetUp();
+    prepareData();
+  }
+
+  @After
+  public void tearDown() throws Exception {
+    session.close();
+    EnvironmentUtils.cleanEnv();
+  }
+
+  @Test
+  public void test() {
+    String[] retArray = new String[]{
+        "0,1,2.0,null",
+        "1,1,2.0,null",
+        "2,1,2.0,null",
+        "3,1,2.0,null",
+        "4,1,2.0,null",
+        "5,1,2.0,4.0",
+        "6,1,2.0,4.0",
+        "7,1,2.0,4.0",
+        "8,1,2.0,4.0",
+        "9,1,2.0,4.0",
+    };
+
+    try {
+      SessionDataSet sessionDataSet = session.executeQueryStatement("select * from root.sg1");
+      sessionDataSet.setBatchSize(1024);
+      DataIterator iterator = sessionDataSet.iterator();
+      int count = 0;
+      while (iterator.next()) {
+        String ans = String.format("%s,%s,%s,%s", iterator.getLong(1), iterator.getInt("root.sg1.d1.s1"),
+            iterator.getFloat(3), iterator.getString("root.sg1.d2.s1"));
+        assertEquals(retArray[count], ans);
+        count++;
+      }
+      assertEquals(retArray.length, count);
+      sessionDataSet.closeOperationHandle();
+    } catch (Exception e) {
+      e.printStackTrace();
+      fail();
+    }
+  }
+
+  private void prepareData() throws IoTDBConnectionException, StatementExecutionException {
+    session = new Session("127.0.0.1", 6667, "root", "root");
+    session.open();
+
+    session.setStorageGroup("root.sg1");
+    session.createTimeseries("root.sg1.d1.s1", TSDataType.INT32, TSEncoding.RLE,
+        CompressionType.SNAPPY);
+    session.createTimeseries("root.sg1.d1.s2", TSDataType.FLOAT, TSEncoding.RLE,
+        CompressionType.SNAPPY);
+    session.createTimeseries("root.sg1.d2.s1", TSDataType.DOUBLE, TSEncoding.RLE,
+        CompressionType.SNAPPY);
+    String deviceId = "root.sg1.d1";
+    List<String> measurements = new ArrayList<>();
+    measurements.add("s1");
+    measurements.add("s2");
+    for (long time = 0; time < 10; time++) {
+      List<String> values = new ArrayList<>();
+      values.add("1");
+      values.add("2");
+      session.insertRecord(deviceId, time, measurements, values);
+    }
+
+    deviceId = "root.sg1.d2";
+    measurements = new ArrayList<>();
+    measurements.add("s1");
+    for (long time = 5; time < 10; time++) {
+      List<String> values = new ArrayList<>();
+      values.add("4");
+      session.insertRecord(deviceId, time, measurements, values);
+    }
+  }
+
+}