Fix upper-case database name in TableSession error

Author: HTHou

integration-test/src/test/java/org/apache/iotdb/relational/it/session/IoTDBTableModelSessionIT.java

@@ -112,4 +112,43 @@ public void testUseDatabase() {
       fail(e.getMessage());
     }
   }
+
+  @Test
+  public void testCreateSessionWithCapitalDB() {
+    final String[] table2Names = new String[] {"table2"};
+    final String[] table2ttls = new String[] {"6600000"};
+
+    try (final ITableSession session =
+        EnvFactory.getEnv().getTableSessionConnectionWithDB("TEST2")) {
+
+      session.executeNonQueryStatement("CREATE DATABASE test1");
+      session.executeNonQueryStatement("CREATE DATABASE test2");
+
+      // or use full qualified table name
+      session.executeNonQueryStatement(
+          "create table test1.table1(region_id STRING ID, plant_id STRING ID, device_id STRING ID, model STRING ATTRIBUTE, temperature FLOAT MEASUREMENT, humidity DOUBLE MEASUREMENT) with (TTL=3600000)");
+
+      session.executeNonQueryStatement(
+          "create table table2(region_id STRING ID, plant_id STRING ID, color STRING ATTRIBUTE, temperature FLOAT MEASUREMENT, speed DOUBLE MEASUREMENT) with (TTL=6600000)");
+
+      try (final SessionDataSet dataSet = session.executeQueryStatement("SHOW TABLES")) {
+        int cnt = 0;
+        assertEquals(showTablesColumnHeaders.size(), dataSet.getColumnNames().size());
+        for (int i = 0; i < showTablesColumnHeaders.size(); i++) {
+          assertEquals(
+              showTablesColumnHeaders.get(i).getColumnName(), dataSet.getColumnNames().get(i));
+        }
+        while (dataSet.hasNext()) {
+          final RowRecord rowRecord = dataSet.next();
+          assertEquals(table2Names[cnt], rowRecord.getFields().get(0).getStringValue());
+          assertEquals(table2ttls[cnt], rowRecord.getFields().get(1).getStringValue());
+          cnt++;
+        }
+        assertEquals(table2Names.length, cnt);
+      }
+
+    } catch (final IoTDBConnectionException | StatementExecutionException e) {
+      fail(e.getMessage());
+    }
+  }
 }

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/protocol/thrift/impl/ClientRPCServiceImpl.java

@@ -208,6 +208,7 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.TimeUnit;
@@ -1230,7 +1231,7 @@ public TSOpenSessionResp openSession(TSOpenSessionReq req) throws TException {
     TSStatus tsStatus = RpcUtils.getStatus(openSessionResp.getCode(), openSessionResp.getMessage());
 
     if (tsStatus.getCode() == TSStatusCode.SUCCESS_STATUS.getStatusCode() && database.isPresent()) {
-      clientSession.setDatabaseName(database.get());
+      clientSession.setDatabaseName(database.get().toLowerCase(Locale.ENGLISH));
     }
     TSOpenSessionResp resp = new TSOpenSessionResp(tsStatus, CURRENT_RPC_VERSION);
     Map<String, String> configuration = new HashMap<>();