Merge pull request #2067 from cherrylzhao/dev

import org.apache.shardingsphere.shardingproxy.backend.communication.jdbc.connection.BackendConnection;

import org.apache.shardingsphere.shardingproxy.backend.response.BackendResponse;

import org.apache.shardingsphere.shardingproxy.backend.response.query.QueryData;

import org.apache.shardingsphere.shardingproxy.backend.schema.LogicSchema;

import org.apache.shardingsphere.shardingproxy.backend.schema.LogicSchemas;

import org.apache.shardingsphere.shardingproxy.backend.text.TextProtocolBackendHandler;

    @Override

    public BackendResponse execute() {

        databaseCommunicationEngine = databaseCommunicationEngineFactory.newTextProtocolInstance(LogicSchemas.getInstance().getLogicSchemas().values().iterator().next(), sql, backendConnection);

        LogicSchema logicSchema = backendConnection.getLogicSchema();

        if (null == logicSchema) {

            logicSchema = LogicSchemas.getInstance().getLogicSchemas().values().iterator().next();

            backendConnection.setCurrentSchema(logicSchema.getName());

        }

        databaseCommunicationEngine = databaseCommunicationEngineFactory.newTextProtocolInstance(logicSchema, sql, backendConnection);

        return databaseCommunicationEngine.execute();

    }

import org.junit.Test;

import org.junit.runner.RunWith;

import org.mockito.Mock;

import org.mockito.Spy;

import org.mockito.junit.MockitoJUnitRunner;

import java.lang.reflect.Field;

import static org.mockito.ArgumentMatchers.any;

import static org.mockito.ArgumentMatchers.anyString;

import static org.mockito.Mockito.mock;

import static org.mockito.Mockito.verify;

import static org.mockito.Mockito.when;

@RunWith(MockitoJUnitRunner.class)

public final class UnicastBackendHandlerTest {

    @Spy

    private BackendConnection backendConnection = new BackendConnection(TransactionType.LOCAL);

    @Mock

        setDatabaseCommunicationEngine(backendHandler);

        BackendResponse actual = backendHandler.execute();

        assertThat(actual, instanceOf(UpdateResponse.class));

        verify(backendConnection).setCurrentSchema(null);

        backendHandler.execute();

    }