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POretrieving values from database in java
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copied!<p>I am making a program that retrieves the inputted data/values of fields from the database I created. But when I'm running it the output is always null. I wonder what's wrong? Here's my code:</p> <pre><code>import java.sql.*; public class GuestsInfo { private String firstName, lastName; private int age; private Connection con; private PreparedStatement statement; public GuestsInfo() { try { Class.forName("com.mysql.jdbc.Driver"); con = DriverManager.getConnection( "jdbc:mysql://localhost:3306/3moronsdb","root",""); } catch (Exception e) { e.printStackTrace(); } } public GuestsInfo(String firstName, String lastName, int age) { this(); try { statement = con.prepareStatement("Insert into guest(firstName,lastName,age)values(?,?,?)"); statement.setString(1, firstName); statement.setString(2, lastName); statement.setInt(3, age); statement.executeUpdate(); con.close(); } catch(Exception e) { e.printStackTrace(); return; } } public void setFirstName(String firstName) { try{ statement= con.prepareStatement("SELECT * FROM guest WHERE firstName = ?"); statement.setString(1, firstName); ResultSet rs = statement.executeQuery(); while(rs.next()){ firstName = rs.getString(1); } }catch(Exception e){ System.out.print(e); } } public String getFirstName(){ return firstName; } public void setLastName(String lastName) { try{ statement= con.prepareStatement("SELECT * FROM guest WHERE lastName = ?"); statement.setString(2, lastName); ResultSet rs = statement.executeQuery(); while(rs.next()){ lastName = rs.getString(2); } }catch(Exception e){ System.out.print(e); } } public String getLastName(){ return lastName; } public void setAge(int age){ try{ statement = con.prepareStatement("SELECT * FROM guest WHERE age=?"); statement.setInt(3, age); ResultSet rs = statement.executeQuery(); while(rs.next()){ age = rs.getInt(3); } }catch(Exception e){ System.out.print(e); } } public int getAge(){ return age; } </code></pre> <p>In my main class I have this codes:</p> <pre><code> public class TestMain { public static void main(String [] args){ GuestsInfo gi = new GuestsInfo(); gi.setFirstName("Ericka"); System.out.println(gi.getFirstName()); } } </code></pre> <p>I wonder why it always says null when I'm running it.</p>

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