例11-3.java

JAVA用Java和XML建立试题库管理系统,试题库管理系统的设计

//例11.3
import java.sql.*;
public class tt
{
  public static void main(String[]args)throws SQLException
  {
    try
    {
      Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
    }
    catch(ClassNotFoundException e)
    {
      System.out.println("error:Driver can't be loaded!");
      System.exit(-1);
    }
    //连接数据库
    Connection con=DriverManager.getConnection("Jdbc:odbc:daitest");
    Statement st=con.createStatement();
    //创建表student,插入两个记录
    st.executeUpdate("Create Table student(id Integer,name varchar(20))");
    
    st.executeUpdate("Insert into student values(100,'Mary')");
    st.executeUpdate("Insert into student values(200,'Tom')");  
    //查询表student的所有记录并输出
    ResultSet rs=st.executeQuery("select * from student");
    System.out.println("Result after Create student");
    dispResult(rs);
    st.executeUpdate("Alter Table student add column address varchar(50)");
    st.executeUpdate("insert into student(id,name,address) values(300,'Alice','Jackson way')");
    rs=st.executeQuery("select * from student");
    System.out.println("Resultafter add column address");
    dispResult(rs);
    //在student表中加入一行
    st.executeUpdate("alter table student Drop column name");
    rs=st.executeQuery("select * from student");
    System.out.println("Result afterdrop column name");
    dispResult(rs);
    rs.close();
    st.executeUpdate("drop table student");//删除student 表
    st.close();
    con.close();
  }
  //显示结果集的子程序
  static void dispResult(ResultSet rs)throws SQLException
  {
    ResultSetMetaData rsmd=rs.getMetaData();
    int nCol=rsmd.getColumnCount();
    while(rs.next())
    {
      int nID=rs.getInt(1);
      String strName=rs.getString(2);
      String strAddress=null;
      if(nCol>2)
      {
        strAddress=rs.getString(3);
      }
      System.out.print(" c1:"+nID);
      System.out.print(" c2:"+strName);  
      System.out.print(" c3:"+strAddress);
      System.out.println();
    }
    System.out.println();
  }
}