在JDBC查询的基础上,使用元数据的一些知识自己制作一个小框架来优化查询语句。同理增、删、改也可以用类似方法,做一下优化。相比JDBC查询要快很多。
1.框 架 架 构 如 下:
2.使用JDBCUtil_Union 连接数据库,主要代码如下
3.编写测试类JDBCUtil_MyUtil2.java
简单查询:
public Account find(int id){
String sql = "select * from account where id =?";
Object params[]={id};
return (Account) JDBCUtil_Union.Query(sql, params,new BeanHandler(Account.class));
public void test4(){
int id = 3;
Account account = find(id);
System.out.println("ID:"+account.getId());
System.out.println("Name:"+account.getName());
System.out.println("Money:"+account.getMoney());
Name:ccc
Money:1000.0}
@Test
}
查询结果:ID:3
Name:ccc
Money:1000.0
复杂查询:
public List getAll(){
String sql = "select * from account";
Object params[] = {};
return (List) JDBCUtil_Union.Query(sql, params, new BeanListHandler(Account.class));}
@Test
public void test5(){
List list = getAll();
System.out.println(list);}
查询结果:[Account [id=1, name=aaa, money=900.0], Account [id=2, name=bbb, money=1000.0], Account [id=3, name=ccc, money=1000.0], Account [id=5, name=aaaaaaaaaaa, money=1000.0], Account [id=6, name=vvvvvv, money=1000.0]]