/*

* Copyright (c) 2004-2013 Tada AB and other contributors, as listed below.

*

* All rights reserved. This program and the accompanying materials

* are made available under the terms of the The BSD 3-Clause License

* which accompanies this distribution, and is available at

* http://opensource.org/licenses/BSD-3-Clause

*

* Contributors:

* Tada AB

* Filip Hrbek

*/

package org.postgresql.pljava.example;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.ArrayList;

import java.util.Iterator;

/**

* Provides a {@link #executeSelect function} that takes any SQL {@code SELECT}

* query as a string, executes it, and returns the {@code ResultSet} produced

* as a single string column, the first row being a header, then one per row

* of the {@code ResultSet}, semicolons delimiting the original columns.

* @author Filip Hrbek

*/

public class ResultSetTest {

public static Iterator<String> executeSelect(String selectSQL) throws SQLException {

if (!selectSQL.toUpperCase().trim().startsWith("SELECT ")) {

throw new SQLException("Not a SELECT statement");

}

return new ResultSetTest(selectSQL).iterator();

}

private ArrayList<String> m_results;

public ResultSetTest(String selectSQL) throws SQLException {

Connection conn = DriverManager

.getConnection("jdbc:default:connection");

m_results = new ArrayList<>();

StringBuffer result;

Statement stmt = conn.createStatement();

ResultSet rs = stmt.executeQuery(selectSQL);

ResultSetMetaData rsmd = rs.getMetaData();

int cnt = rsmd.getColumnCount();

result = new StringBuffer();

for (int i = 1; i <= cnt; i++) {

result.append((rsmd.getColumnName(i) + "("

+ rsmd.getColumnClassName(i) + ")").replaceAll("(\\\\|;)",

"\\$1") + ";");

}

m_results.add(result.toString());

while (rs.next()) {

result = new StringBuffer();

Object rsObject = null;

for (int i = 1; i <= cnt; i++) {

rsObject = rs.getObject(i);

if (rsObject == null) {

rsObject = "<NULL>";

}

result.append(rsObject.toString()

.replaceAll("(\\\\|;)", "\\$1") + ";");

}

m_results.add(result.toString());

}

rs.close();

}

public void close() {

}

private Iterator<String> iterator() {

return m_results.iterator();

}

}