JDBC学习

JDBC的常用对象

  1. DriverManager
  2. Connection
  3. PreparedStatement
  4. Statement
 

  5. public Connection getConnection()throws Exception{
     
      return java.sql.DriverManager.getConnection(dbUrl,dbUser,dbPwd);
    }

  6. JDBC的执行过程
   

    Connection con=null;
    PreparedStatement stmt=null;
    try {
      con=getConnection(); 

     
      con.setAutoCommit(false);

      
      if(customer.getName()==null)
        throw new BusinessException("");

      

      
      long customerId=getNextId(con,"CUSTOMERS");
      
      stmt=con.prepareStatement("insert into CUSTOMERS(ID,NAME,AGE) values(?,?,?)");
      stmt.setLong(1,customerId);
      stmt.setString(2,customer.getName());
      stmt.setInt(3,customer.getAge());
      stmt.execute();
      con.commit();
    }
    catch(Exception e){
      e.printStackTrace();
      try{
        con.rollback();
      }catch(SQLException sqlex){
        sqlex.printStackTrace(System.out);
      }
      throw e;
    }finally{
      try{
         stmt.close();
         con.close();
       }catch(Exception e){
         e.printStackTrace();
       }
    }

   7. JDBC的缺点
     a. 冗余代码太多
     b. 可扩展性差