Fix Postgres execute error sql no response (#3129) (#4039)

sharding-proxy/sharding-proxy-frontend/sharding-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/shardingproxy/frontend/mysql/command/query/binary/execute/MySQLComStmtExecuteExecutor.java

@@ -60,6 +60,8 @@ public final class MySQLComStmtExecuteExecutor implements QueryCommandExecutor {
     
     private volatile boolean isQuery;
     
+    private volatile boolean isErrorResponse;
+    
     private int currentSequenceId;
     
     public MySQLComStmtExecuteExecutor(final MySQLComStmtExecutePacket comStmtExecutePacket, final BackendConnection backendConnection) {
@@ -74,6 +76,7 @@ public final class MySQLComStmtExecuteExecutor implements QueryCommandExecutor {
         }
         BackendResponse backendResponse = databaseCommunicationEngine.execute();
         if (backendResponse instanceof ErrorResponse) {
+            isErrorResponse = true;
             return Collections.<DatabasePacket>singletonList(createErrorPacket(((ErrorResponse) backendResponse).getCause()));
         }
         if (backendResponse instanceof UpdateResponse) {
@@ -108,6 +111,11 @@ public final class MySQLComStmtExecuteExecutor implements QueryCommandExecutor {
         return isQuery;
     }
     
+    @Override
+    public boolean isErrorResponse() {
+        return isErrorResponse;
+    }
+    
     @Override
     public boolean next() throws SQLException {
         return databaseCommunicationEngine.next();

sharding-proxy/sharding-proxy-frontend/sharding-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/shardingproxy/frontend/mysql/command/query/text/query/MySQLComQueryPacketExecutor.java

@@ -59,6 +59,8 @@ public final class MySQLComQueryPacketExecutor implements QueryCommandExecutor {
     
     private volatile boolean isQuery;
     
+    private volatile boolean isErrorResponse;
+    
     private int currentSequenceId;
     
     public MySQLComQueryPacketExecutor(final MySQLComQueryPacket comQueryPacket, final BackendConnection backendConnection) {
@@ -72,6 +74,7 @@ public final class MySQLComQueryPacketExecutor implements QueryCommandExecutor {
         }
         BackendResponse backendResponse = textProtocolBackendHandler.execute();
         if (backendResponse instanceof ErrorResponse) {
+            isErrorResponse = true;
             return Collections.<DatabasePacket>singletonList(createErrorPacket(((ErrorResponse) backendResponse).getCause()));
         }
         if (backendResponse instanceof UpdateResponse) {
@@ -123,6 +126,11 @@ public final class MySQLComQueryPacketExecutor implements QueryCommandExecutor {
         return isQuery;
     }
     
+    @Override
+    public boolean isErrorResponse() {
+        return isErrorResponse;
+    }
+    
     @Override
     public boolean next() throws SQLException {
         return textProtocolBackendHandler.next();

sharding-proxy/sharding-proxy-frontend/sharding-proxy-frontend-mysql/src/test/java/org/apache/shardingsphere/shardingproxy/frontend/mysql/command/query/binary/execute/MySQLComStmtExecuteExecutorTest.java

+/*
+ * 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.shardingsphere.shardingproxy.frontend.mysql.command.query.binary.execute;
+
+import lombok.SneakyThrows;
+import org.apache.shardingsphere.shardingproxy.backend.communication.DatabaseCommunicationEngine;
+import org.apache.shardingsphere.shardingproxy.backend.communication.jdbc.connection.BackendConnection;
+import org.apache.shardingsphere.shardingproxy.backend.response.error.ErrorResponse;
+import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.command.query.binary.execute.MySQLComStmtExecutePacket;
+import org.hamcrest.Matchers;
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.internal.util.reflection.FieldSetter;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import java.sql.SQLException;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+@RunWith(MockitoJUnitRunner.class)
+public class MySQLComStmtExecuteExecutorTest {
+    
+    @Mock
+    private SQLException sqlException;
+    
+    @Mock
+    private DatabaseCommunicationEngine databaseCommunicationEngine;
+    
+    @Test
+    @SneakyThrows
+    public void assertIsErrorResponse() {
+        MySQLComStmtExecuteExecutor mySQLComStmtExecuteExecutor = new MySQLComStmtExecuteExecutor(mock(MySQLComStmtExecutePacket.class), mock(BackendConnection.class));
+        FieldSetter.setField(mySQLComStmtExecuteExecutor, MySQLComStmtExecuteExecutor.class.getDeclaredField("databaseCommunicationEngine"), databaseCommunicationEngine);
+        when(sqlException.getCause()).thenReturn(new Exception());
+        when(databaseCommunicationEngine.execute()).thenReturn(new ErrorResponse(sqlException));
+        mySQLComStmtExecuteExecutor.execute();
+        Assert.assertThat(mySQLComStmtExecuteExecutor.isErrorResponse(), Matchers.is(true));
+    }
+}

sharding-proxy/sharding-proxy-frontend/sharding-proxy-frontend-mysql/src/test/java/org/apache/shardingsphere/shardingproxy/frontend/mysql/command/query/text/query/MySQLComQueryPacketExecutorTest.java

+/*
+ * 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.shardingsphere.shardingproxy.frontend.mysql.command.query.text.query;
+
+import lombok.SneakyThrows;
+import org.apache.shardingsphere.shardingproxy.backend.response.error.ErrorResponse;
+import org.apache.shardingsphere.shardingproxy.backend.text.TextProtocolBackendHandler;
+import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.command.query.text.query.MySQLComQueryPacket;
+import org.hamcrest.Matchers;
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.internal.util.reflection.FieldSetter;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import java.sql.SQLException;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+@RunWith(MockitoJUnitRunner.class)
+public class MySQLComQueryPacketExecutorTest {
+    
+    @Mock
+    private SQLException sqlException;
+    
+    @Mock
+    private TextProtocolBackendHandler textProtocolBackendHandler;
+    
+    @Test
+    @SneakyThrows
+    public void assertIsErrorResponse() {
+        MySQLComQueryPacketExecutor mySQLComQueryPacketExecutor = new MySQLComQueryPacketExecutor(mock(MySQLComQueryPacket.class), null);
+        FieldSetter.setField(mySQLComQueryPacketExecutor, MySQLComQueryPacketExecutor.class.getDeclaredField("textProtocolBackendHandler"), textProtocolBackendHandler);
+        when(sqlException.getCause()).thenReturn(new Exception());
+        when(textProtocolBackendHandler.execute()).thenReturn(new ErrorResponse(sqlException));
+        mySQLComQueryPacketExecutor.execute();
+        Assert.assertThat(mySQLComQueryPacketExecutor.isErrorResponse(), Matchers.is(true));
+    }
+}

sharding-proxy/sharding-proxy-frontend/sharding-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/frontend/postgresql/PostgreSQLErrPacketFactory.java

+/*
+ * 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.shardingsphere.shardingproxy.frontend.postgresql;
+
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+import org.apache.shardingsphere.shardingproxy.transport.postgresql.packet.generic.PostgreSQLErrorResponsePacket;
+import org.postgresql.util.PSQLException;
+import org.postgresql.util.ServerErrorMessage;
+
+/**
+ * ERR packet factory for PostgreSQL.
+ * 
+ * @author avalon566
+ */
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public final class PostgreSQLErrPacketFactory {
+    
+    /**
+     * New instance of PostgreSQL ERR packet.
+     * 
+     * @param cause cause
+     * @return instance of PostgreSQL ERR packet
+     */
+    public static PostgreSQLErrorResponsePacket newInstance(final Exception cause) {
+        if (cause instanceof PSQLException) {
+            ServerErrorMessage serverErrorMessage = ((PSQLException) cause).getServerErrorMessage();
+            PostgreSQLErrorResponsePacket errorResponsePacket = new PostgreSQLErrorResponsePacket();
+            errorResponsePacket.addField(PostgreSQLErrorResponsePacket.FIELD_TYPE_SEVERITY, serverErrorMessage.getSeverity());
+            errorResponsePacket.addField(PostgreSQLErrorResponsePacket.FIELD_TYPE_CODE, serverErrorMessage.getSQLState());
+            errorResponsePacket.addField(PostgreSQLErrorResponsePacket.FIELD_TYPE_MESSAGE, serverErrorMessage.getMessage());
+            errorResponsePacket.addField(PostgreSQLErrorResponsePacket.FIELD_TYPE_POSITION, Integer.toString(serverErrorMessage.getPosition()));
+            return errorResponsePacket;
+        }
+        return new PostgreSQLErrorResponsePacket();
+    }
+}

sharding-proxy/sharding-proxy-frontend/sharding-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/frontend/postgresql/command/PostgreSQLCommandExecuteEngine.java

@@ -74,6 +74,10 @@ public final class PostgreSQLCommandExecuteEngine implements CommandExecuteEngin
             context.write(new PostgreSQLReadyForQueryPacket());
             return;
         }
+        if (queryCommandExecutor.isErrorResponse()) {
+            context.write(new PostgreSQLReadyForQueryPacket());
+            return;
+        }
         int count = 0;
         int proxyFrontendFlushThreshold = ShardingProxyContext.getInstance().getProperties().<Integer>getValue(PropertiesConstant.PROXY_FRONTEND_FLUSH_THRESHOLD);
         while (queryCommandExecutor.next()) {

sharding-proxy/sharding-proxy-frontend/sharding-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/frontend/postgresql/command/query/binary/bind/PostgreSQLComBindExecutor.java

@@ -29,6 +29,7 @@ import org.apache.shardingsphere.shardingproxy.backend.response.query.QueryRespo
 import org.apache.shardingsphere.shardingproxy.backend.response.update.UpdateResponse;
 import org.apache.shardingsphere.shardingproxy.context.ShardingProxyContext;
 import org.apache.shardingsphere.shardingproxy.frontend.api.QueryCommandExecutor;
+import org.apache.shardingsphere.shardingproxy.frontend.postgresql.PostgreSQLErrPacketFactory;
 import org.apache.shardingsphere.shardingproxy.transport.packet.DatabasePacket;
 import org.apache.shardingsphere.shardingproxy.transport.postgresql.constant.PostgreSQLColumnType;
 import org.apache.shardingsphere.shardingproxy.transport.postgresql.packet.PostgreSQLPacket;
@@ -62,6 +63,8 @@ public final class PostgreSQLComBindExecutor implements QueryCommandExecutor {
     
     private volatile boolean isQuery;
     
+    private volatile boolean isErrorResponse;
+    
     public PostgreSQLComBindExecutor(final PostgreSQLComBindPacket packet, final BackendConnection backendConnection) {
         this.packet = packet;
         databaseCommunicationEngine = null == packet.getSql()
@@ -80,6 +83,7 @@ public final class PostgreSQLComBindExecutor implements QueryCommandExecutor {
         }
         BackendResponse backendResponse = databaseCommunicationEngine.execute();
         if (backendResponse instanceof ErrorResponse) {
+            isErrorResponse = true;
             result.add(createErrorPacket((ErrorResponse) backendResponse));
         }
         if (backendResponse instanceof UpdateResponse) {
@@ -95,7 +99,7 @@ public final class PostgreSQLComBindExecutor implements QueryCommandExecutor {
     }
     
     private PostgreSQLErrorResponsePacket createErrorPacket(final ErrorResponse errorResponse) {
-        return new PostgreSQLErrorResponsePacket();
+        return PostgreSQLErrPacketFactory.newInstance(errorResponse.getCause());
     }
     
     private PostgreSQLCommandCompletePacket createUpdatePacket(final UpdateResponse updateResponse) {
@@ -125,6 +129,11 @@ public final class PostgreSQLComBindExecutor implements QueryCommandExecutor {
         return isQuery;
     }
     
+    @Override
+    public boolean isErrorResponse() {
+        return isErrorResponse;
+    }
+    
     @Override
     public boolean next() throws SQLException {
         return null != databaseCommunicationEngine && databaseCommunicationEngine.next();

sharding-proxy/sharding-proxy-frontend/sharding-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/frontend/postgresql/command/query/text/PostgreSQLComQueryExecutor.java

@@ -18,6 +18,7 @@
 package org.apache.shardingsphere.shardingproxy.frontend.postgresql.command.query.text;
 
 import com.google.common.base.Optional;
+import org.apache.shardingsphere.shardingproxy.frontend.postgresql.PostgreSQLErrPacketFactory;
 import org.apache.shardingsphere.underlying.common.database.type.DatabaseTypes;
 import org.apache.shardingsphere.shardingproxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.shardingproxy.backend.response.BackendResponse;
@@ -56,6 +57,8 @@ public final class PostgreSQLComQueryExecutor implements QueryCommandExecutor {
     
     private volatile boolean isQuery;
     
+    private volatile boolean isErrorResponse;
+    
     public PostgreSQLComQueryExecutor(final PostgreSQLComQueryPacket comQueryPacket, final BackendConnection backendConnection) {
         textProtocolBackendHandler = TextProtocolBackendHandlerFactory.newInstance(DatabaseTypes.getActualDatabaseType("PostgreSQL"), comQueryPacket.getSql(), backendConnection);
     }
@@ -67,6 +70,7 @@ public final class PostgreSQLComQueryExecutor implements QueryCommandExecutor {
         }
         BackendResponse backendResponse = textProtocolBackendHandler.execute();
         if (backendResponse instanceof ErrorResponse) {
+            isErrorResponse = true;
             return Collections.<DatabasePacket>singletonList(createErrorPacket((ErrorResponse) backendResponse));
         }
         if (backendResponse instanceof UpdateResponse) {
@@ -77,7 +81,7 @@ public final class PostgreSQLComQueryExecutor implements QueryCommandExecutor {
     }
     
     private PostgreSQLErrorResponsePacket createErrorPacket(final ErrorResponse errorResponse) {
-        return new PostgreSQLErrorResponsePacket();
+        return PostgreSQLErrPacketFactory.newInstance(errorResponse.getCause());
     }
     
     private PostgreSQLCommandCompletePacket createUpdatePacket(final UpdateResponse updateResponse) {
@@ -107,6 +111,11 @@ public final class PostgreSQLComQueryExecutor implements QueryCommandExecutor {
         return isQuery;
     }
     
+    @Override
+    public boolean isErrorResponse() {
+        return isErrorResponse;
+    }
+    
     @Override
     public boolean next() throws SQLException {
         return textProtocolBackendHandler.next();

sharding-proxy/sharding-proxy-frontend/sharding-proxy-frontend-postgresql/src/test/java/org/apache/shardingsphere/shardingproxy/frontend/postgresql/command/PostgreSQLCommandExecuteEngineTest.java

+/*
+ * 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.shardingsphere.shardingproxy.frontend.postgresql.command;
+
+import io.netty.channel.ChannelHandlerContext;
+import lombok.SneakyThrows;
+import org.apache.shardingsphere.shardingproxy.frontend.api.QueryCommandExecutor;
+import org.apache.shardingsphere.shardingproxy.transport.postgresql.packet.generic.PostgreSQLReadyForQueryPacket;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import static org.mockito.ArgumentMatchers.isA;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@RunWith(MockitoJUnitRunner.class)
+public class PostgreSQLCommandExecuteEngineTest {
+    
+    @Mock
+    private ChannelHandlerContext channelHandlerContext;
+    
+    @Mock
+    private QueryCommandExecutor queryCommandExecutor;
+    
+    @Test
+    @SneakyThrows
+    public void assertWriteQueryDataWithError() {
+        PostgreSQLCommandExecuteEngine postgreSQLCommandExecuteEngine = new PostgreSQLCommandExecuteEngine();
+        when(queryCommandExecutor.isQuery()).thenReturn(false);
+        when(queryCommandExecutor.isErrorResponse()).thenReturn(true);
+        postgreSQLCommandExecuteEngine.writeQueryData(channelHandlerContext, null, queryCommandExecutor, 0);
+        verify(channelHandlerContext, times(1)).write(isA(PostgreSQLReadyForQueryPacket.class));
+    }
+}

sharding-proxy/sharding-proxy-frontend/sharding-proxy-frontend-postgresql/src/test/java/org/apache/shardingsphere/shardingproxy/frontend/postgresql/command/query/binary/bind/PostgreSQLComBindExecutorTest.java

+/*
+ * 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.shardingsphere.shardingproxy.frontend.postgresql.command.query.binary.bind;
+
+import lombok.SneakyThrows;
+import org.apache.shardingsphere.shardingproxy.backend.communication.DatabaseCommunicationEngine;
+import org.apache.shardingsphere.shardingproxy.backend.response.error.ErrorResponse;
+import org.apache.shardingsphere.shardingproxy.transport.postgresql.packet.command.query.binary.bind.PostgreSQLComBindPacket;
+import org.apache.shardingsphere.shardingproxy.transport.postgresql.packet.generic.PostgreSQLErrorResponsePacket;
+import org.hamcrest.Matchers;
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.internal.util.reflection.FieldSetter;
+import org.mockito.junit.MockitoJUnitRunner;
+import org.postgresql.util.PSQLException;
+import org.postgresql.util.ServerErrorMessage;
+
+import java.util.LinkedList;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+@RunWith(MockitoJUnitRunner.class)
+public class PostgreSQLComBindExecutorTest {
+    
+    @Mock
+    private DatabaseCommunicationEngine databaseCommunicationEngine;
+    
+    @Test
+    @SneakyThrows
+    public void assertExecuteHasError() {
+        PostgreSQLComBindExecutor postgreSQLComBindExecutor = new PostgreSQLComBindExecutor(mock(PostgreSQLComBindPacket.class), null);
+        FieldSetter.setField(postgreSQLComBindExecutor, PostgreSQLComBindExecutor.class.getDeclaredField("databaseCommunicationEngine"), databaseCommunicationEngine);
+        ErrorResponse errorResponse = new ErrorResponse(new PSQLException(mock(ServerErrorMessage.class)));
+        when(databaseCommunicationEngine.execute()).thenReturn(errorResponse);
+        Assert.assertThat(((LinkedList) postgreSQLComBindExecutor.execute()).get(1), Matchers.instanceOf(PostgreSQLErrorResponsePacket.class));
+        Assert.assertThat(postgreSQLComBindExecutor.isErrorResponse(), Matchers.is(true));
+    }
+}

sharding-proxy/sharding-proxy-frontend/sharding-proxy-frontend-postgresql/src/test/java/org/apache/shardingsphere/shardingproxy/frontend/postgresql/command/query/text/PostgreSQLComQueryExecutorTest.java

+/*
+ * 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.shardingsphere.shardingproxy.frontend.postgresql.command.query.text;
+
+import lombok.SneakyThrows;
+import org.apache.shardingsphere.shardingproxy.backend.response.error.ErrorResponse;
+import org.apache.shardingsphere.shardingproxy.backend.text.TextProtocolBackendHandler;
+import org.apache.shardingsphere.shardingproxy.transport.postgresql.packet.command.query.text.PostgreSQLComQueryPacket;
+import org.apache.shardingsphere.shardingproxy.transport.postgresql.packet.generic.PostgreSQLErrorResponsePacket;
+import org.hamcrest.Matchers;
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.internal.util.reflection.FieldSetter;
+import org.mockito.junit.MockitoJUnitRunner;
+import org.postgresql.util.PSQLException;
+import org.postgresql.util.ServerErrorMessage;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+@RunWith(MockitoJUnitRunner.class)
+public class PostgreSQLComQueryExecutorTest {
+    
+    @Mock
+    private TextProtocolBackendHandler textProtocolBackendHandler;
+    
+    @Test
+    @SneakyThrows
+    public void assertExecuteReturnErrorResponsePacket() {
+        PostgreSQLComQueryExecutor postgreSQLComQueryExecutor = new PostgreSQLComQueryExecutor(mock(PostgreSQLComQueryPacket.class), null);
+        FieldSetter.setField(postgreSQLComQueryExecutor, PostgreSQLComQueryExecutor.class.getDeclaredField("textProtocolBackendHandler"), textProtocolBackendHandler);
+        ErrorResponse errorResponse = new ErrorResponse(new PSQLException(mock(ServerErrorMessage.class)));
+        when(textProtocolBackendHandler.execute()).thenReturn(errorResponse);
+        Assert.assertThat(postgreSQLComQueryExecutor.execute().iterator().next(), Matchers.instanceOf(PostgreSQLErrorResponsePacket.class));
+        Assert.assertThat(postgreSQLComQueryExecutor.isErrorResponse(), Matchers.is(true));
+    }
+}

sharding-proxy/sharding-proxy-frontend/sharding-proxy-frontend-spi/src/main/java/org/apache/shardingsphere/shardingproxy/frontend/api/QueryCommandExecutor.java

@@ -28,6 +28,13 @@ import java.sql.SQLException;
  */
 public interface QueryCommandExecutor extends CommandExecutor {
     
+    /**
+     * Judge is error response.
+     *
+     * @return is error response or not
+     */
+    boolean isErrorResponse();
+    
     /**
      * Judge is query SQL or not.
      *