testnullvalues.java

来自「此程序都是企业级 的数据库开发程序 全面揭示了JAVA对数据库的操作」· Java 代码 · 共 40 行

package results;

import java.sql.*;
import connections.*;

public class TestNullValues {
  public static void main(String[] args) {
    String sql = "SELECT recordingid, recordingtitle, coverimagefilespec " 
                 + "FROM recordings";
    Connection connection = null;
    Statement queryRecordings = null;
    ResultSet results = null;

    try {
      connection = ConnectionFactory.getConnection();
      queryRecordings = connection.createStatement();
      results = queryRecordings.executeQuery(sql);

      String title, coverimagefilespec;
      int id;
      while (results.next()) {
        id = results.getInt("RECORDINGID");
        title = results.getString("RECORDINGTITLE");
        coverimagefilespec = results.getString("COVERIMAGEFILESPEC");
        if (results.wasNull()) {
          coverimagefilespec = "[no cover graphic]";
        } 
        System.out.println(id + ", " + title.trim() + ", " 
                           + coverimagefilespec.trim());
      } 
    } catch (Exception e) {
      e.printStackTrace();
    } 
    finally {
      ConnectionFactory.close(results);
      ConnectionFactory.close(queryRecordings);
      ConnectionFactory.close(connection);
    } 
  } 
}