Github user leskin-in commented on a diff in the pull request:
https://github.com/apache/incubator-hawq/pull/1353#discussion_r193745222
--- Diff:
pxf/pxf-jdbc/src/main/java/org/apache/hawq/pxf/plugins/jdbc/JdbcAccessor.java
---
@@ -0,0 +1,469 @@
+package org.apache.hawq.pxf.plugins.jdbc;
+
+/*
+ * 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.
+ */
+
+import org.apache.hawq.pxf.api.OneRow;
+import org.apache.hawq.pxf.api.OneField;
+import org.apache.hawq.pxf.api.ReadAccessor;
+import org.apache.hawq.pxf.api.WriteAccessor;
+import org.apache.hawq.pxf.api.io.DataType;
+import org.apache.hawq.pxf.api.UserDataException;
+import org.apache.hawq.pxf.api.utilities.ColumnDescriptor;
+import org.apache.hawq.pxf.api.utilities.InputData;
+
+import java.util.List;
+import java.io.IOException;
+import java.text.ParseException;
+import java.math.BigDecimal;
+import java.sql.Types;
+import java.sql.Date;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.SQLTimeoutException;
+import java.sql.Statement;
+import java.sql.Timestamp;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+/**
+ * JDBC tables accessor
+ *
+ * The SELECT queries are processed by {@link java.sql.Statement}
+ *
+ * The INSERT queries are processed by {@link java.sql.PreparedStatement}
and
+ * built-in JDBC batches of arbitrary size
+ */
+public class JdbcAccessor extends JdbcPlugin implements ReadAccessor,
WriteAccessor {
+ /**
+ * Class constructor
+ */
+ public JdbcAccessor(InputData inputData) throws UserDataException {
+ super(inputData);
+ }
+
+ /**
+ * openForRead() implementation
+ * Create query, open JDBC connection, execute query and store the
result into resultSet
+ *
+ * @throws SQLException if a database access error occurs
+ * @throws SQLTimeoutException if a problem with the connection occurs
+ * @throws ParseException if th SQL statement provided in PXF
InputData is incorrect
+ * @throws ClassNotFoundException if the superclass implementation
disappeared
+ */
+ @Override
+ public boolean openForRead() throws SQLException, SQLTimeoutException,
ParseException, ClassNotFoundException {
+ if (statementRead != null && !statementRead.isClosed()) {
+ return true;
+ }
+
+ super.openConnection();
+
+ queryRead = buildSelectQuery();
+ statementRead = dbConn.createStatement();
+ resultSetRead = statementRead.executeQuery(queryRead);
+
+ return true;
+ }
+
+ /**
+ * readNextObject() implementation
+ * Retreive the next tuple from resultSet and return it
+ *
+ * @throws SQLException if a problem in resultSet occurs
+ */
+ @Override
+ public OneRow readNextObject() throws SQLException {
+ if (resultSetRead.next()) {
+ return new OneRow(resultSetRead);
+ }
+ return null;
+ }
+
+ /**
+ * closeForRead() implementation
+ *
+ * @throws SQLException if a database access error occurs
+ */
+ @Override
+ public void closeForRead() throws SQLException {
+ if (statementRead != null && !statementRead.isClosed()) {
+ statementRead.close();
+ statementRead = null;
+ }
+ super.closeConnection();
+ }
+
+ /**
+ * openForWrite() implementation
+ * Create query template and open JDBC connection
+ *
+ * @throws SQLException if a database access error occurs
+ * @throws SQLTimeoutException if a problem with the connection occurs
+ * @throws ParseException if the SQL statement provided in PXF
InputData is incorrect
+ * @throws ClassNotFoundException if the superclass implementation has
disappeared
+ */
+ @Override
+ public boolean openForWrite() throws SQLException,
SQLTimeoutException, ParseException, ClassNotFoundException {
+ if (statementWrite != null && !statementWrite.isClosed()) {
--- End diff --
Fixed:
https://github.com/apache/incubator-hawq/pull/1353/commits/b877c908ef202872364ccbfc20761116aa939ccf#diff-6829beb5b62de0a4880b5d5dbebca91aR127.
Note that in the current version of PXF, this procedure is always called
once.
---
