diff --git a/src/main/java/com/alibaba/druid/sql/ast/statement/SQLSelect.java b/src/main/java/com/alibaba/druid/sql/ast/statement/SQLSelect.java
index 115207ae37..3d32fa2199 100644
--- a/src/main/java/com/alibaba/druid/sql/ast/statement/SQLSelect.java
+++ b/src/main/java/com/alibaba/druid/sql/ast/statement/SQLSelect.java
@@ -20,7 +20,9 @@ import java.util.List;
 
 import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.*;
+import com.alibaba.druid.sql.dialect.oracle.ast.OracleSQLObject;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class SQLSelect extends SQLObjectImpl {
 
@@ -150,6 +152,18 @@ public class SQLSelect extends SQLObjectImpl {
                 return SQLUtils.toSQLString(this, dbType);
             }
         }
+
+        if (parent instanceof OracleSQLObject) {
+            return SQLUtils.toSQLString(this, JdbcConstants.ORACLE);
+        }
+
+        if (query instanceof SQLSelectQueryBlock) {
+            String dbType = ((SQLSelectQueryBlock) query).dbType;
+
+            if (dbType != null) {
+                return SQLUtils.toSQLString(this, dbType);
+            }
+        }
         
         return super.toString();
     }
diff --git a/src/test/java/com/alibaba/druid/bvt/sql/oracle/OracleMergeTest11.java b/src/test/java/com/alibaba/druid/bvt/sql/oracle/OracleMergeTest11.java
new file mode 100644
index 0000000000..f91f3a292a
--- /dev/null
+++ b/src/test/java/com/alibaba/druid/bvt/sql/oracle/OracleMergeTest11.java
@@ -0,0 +1,84 @@
+/*
+ * Copyright 1999-2017 Alibaba Group Holding Ltd.
+ *
+ * Licensed 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 com.alibaba.druid.bvt.sql.oracle;
+
+import com.alibaba.druid.sql.OracleTest;
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.ast.statement.SQLMergeStatement;
+import com.alibaba.druid.sql.ast.statement.SQLSelect;
+import com.alibaba.druid.sql.ast.statement.SQLSubqueryTableSource;
+import com.alibaba.druid.sql.dialect.oracle.parser.OracleStatementParser;
+import com.alibaba.druid.sql.parser.SQLStatementParser;
+import org.junit.Assert;
+
+import java.util.List;
+
+public class OracleMergeTest11 extends OracleTest {
+
+    public void test_0() throws Exception {
+        String sql = "MERGE INTO (\n" +
+                "SELECT *\n" +
+                "FROM KPI_M_CW_INCOME_FACT_BAK\n" +
+                "WHERE THE_DATE = '{THISMONTH}'\n" +
+                "AND AREA_LEVEL <= 1\n" +
+                "AND TYPE_ID = '2'\n" +
+                ") A\n" +
+                "USING (\n" +
+                "SELECT *\n" +
+                "FROM M_HEALTH_APPRAISE_LOAD\n" +
+                "WHERE THE_DATE = TRUNC(SYSDATE)\n" +
+                "AND AREA_LEVEL <= 1\n" +
+                ") B ON (A.AREA_ID = B.AREA_ID\n" +
+                "AND A.AREA_LEVEL = B.AREA_LEVEL)\n" +
+                "WHEN MATCHED THEN UPDATE SET A.SUM_CHRG_YS = ROUND(B.TOTAL_CHARGE * 1.00 / 10000, 2), A.CHARGE = B.THIS_CHARGE;";
+
+        SQLStatementParser parser = new OracleStatementParser(sql);
+        List<SQLStatement> stmtList = parser.parseStatementList();
+        SQLMergeStatement mergeStatement = (SQLMergeStatement) stmtList.get(0);
+        String result = SQLUtils.toOracleString(mergeStatement);
+        Assert.assertEquals("MERGE INTO (\n" +
+                        "\tSELECT *\n" +
+                        "\tFROM KPI_M_CW_INCOME_FACT_BAK\n" +
+                        "\tWHERE THE_DATE = '{THISMONTH}'\n" +
+                        "\t\tAND AREA_LEVEL <= 1\n" +
+                        "\t\tAND TYPE_ID = '2'\n" +
+                        ") A\n" +
+                        "USING (\n" +
+                        "\tSELECT *\n" +
+                        "\tFROM M_HEALTH_APPRAISE_LOAD\n" +
+                        "\tWHERE THE_DATE = TRUNC(SYSDATE)\n" +
+                        "\t\tAND AREA_LEVEL <= 1\n" +
+                        ") B ON (A.AREA_ID = B.AREA_ID\n" +
+                        "AND A.AREA_LEVEL = B.AREA_LEVEL) \n" +
+                        "WHEN MATCHED THEN UPDATE SET A.SUM_CHRG_YS = ROUND(B.TOTAL_CHARGE * 1.00 / 10000, 2), A.CHARGE = B.THIS_CHARGE;",
+                            result);
+
+        SQLSelect select = ((SQLSubqueryTableSource)mergeStatement.getInto()).getSelect();
+        assertEquals("SELECT *\n" +
+                "FROM KPI_M_CW_INCOME_FACT_BAK\n" +
+                "WHERE THE_DATE = '{THISMONTH}'\n" +
+                "\tAND AREA_LEVEL <= 1\n" +
+                "\tAND TYPE_ID = '2'", select.toString());
+
+        // Assert.assertTrue(visitor.getColumns().contains(new TableStat.Column("employees", "employee_id")));
+        // Assert.assertTrue(visitor.getColumns().contains(new TableStat.Column("employees", "salary")));
+        // Assert.assertTrue(visitor.getColumns().contains(new TableStat.Column("employees", "department_id")));
+        // Assert.assertTrue(visitor.getColumns().contains(new TableStat.Column("bonuses", "employee_id")));
+        // Assert.assertTrue(visitor.getColumns().contains(new TableStat.Column("bonuses", "bonus")));
+    }
+
+}