simpleselect.java

weblogic应用全实例

package examples.jdbc.informix4;

import java.sql.*;
import java.util.Properties;

/**
 * 
 * 这个实例演示如何用JDBC查询数据和结果集。
 */

public class simpleselect {
  
  public static void main(String argv[])
  {
//声明连接，SQL语句和结果集变量
    java.sql.Connection conn = null;
    java.sql.ResultSet rs    = null;
    java.sql.Statement stmt  = null;
    
    try {
    	//声明属性变量
      Properties props = new Properties();
      props.put("user",     "informix");
      props.put("password", "secret");
      props.put("server",   "myDBHost"); // Informix服务器运行的主机名
      props.put("port",     "1493");       // Informix服务器的监听端口
      props.put("db",       "myDB");  // Informix服务器数据库名
    
      //加载数据库驱动程序
      Driver myDriver = (Driver) Class.forName("weblogic.jdbc.informix4.Driver").newInstance();
      //创建连接
      conn = myDriver.connect("jdbc:weblogic:informix4", props);
    //创建SQL语句对象
      stmt = conn.createStatement();
    //执行SQL语句
      stmt.execute("select * from empdemo");
    //取得结果集
      rs = stmt.getResultSet();
    //打印结果
      while (rs.next()) {
          System.out.println(rs.getString("empid") + " - " + 
                             rs.getString("name")  + " - " + 
                             rs.getString("dept"));
      }
    //获得元数据对象
      ResultSetMetaData rsmd = rs.getMetaData();
      //获取并打印列数
      System.out.println("Number of Columns: " + rsmd.getColumnCount());
      //打印表结构信息
      for (int i = 1; i <= rsmd.getColumnCount(); i++) {
          System.out.println("Column Name: "          + rsmd.getColumnName(i));
          System.out.println("Nullable: "             + rsmd.isNullable(i));
          System.out.println("Precision: "            + rsmd.getPrecision(i));
          System.out.println("Scale: "                + rsmd.getScale(i));
          System.out.println("Size: "                 + rsmd.getColumnDisplaySize(i));
          System.out.println("Column Type: "          + rsmd.getColumnType(i));
          System.out.println("Column Type Name: "     + rsmd.getColumnTypeName(i));
          System.out.println("");
      }
    } catch (Exception e) {
    //异常处理
        System.out.println("Exception was thrown: " + e.getMessage());
    } finally {
    	//关闭连接
        try {
          if (stmt != null)
            stmt.close();
          if (rs != null)
            rs.close();
          if (conn != null)
            conn.close();
        } catch (SQLException sqle) {
            System.out.println("SQLException was thrown: " + sqle.getMessage());
        }
    }
  }
}