开发者学堂课程【JDBC 数据库开发进阶：dbUtils 结果集处理器介绍】学习笔记，与课程紧密联系，让用户快速学习知识。
课程地址：https://developer.aliyun.com/learning/course/32/detail/691
dbUtils 结果集处理器介绍
内容介绍
一.update 方法
二.query 方法
三.开始测试
一.update 方法
int update( string sql，object, …params) 可执行增、删改语句
int update( connection con, String aql, Object... params) 需要调用者提供 Connection，这说明本方法不再管 Cesnection，支持事务！
二.query 方法:
T query( String sql, ReaultSetHandler rsh, Object…params) 可执行查询
它会先得到 ResultSet,然后请用 rsh 的 handle()把 rs 转换成需要的类型!
T update( Connection con, String aql, ResultSetHadler rsh ,Object... params) 支持事务。
三.开始测试
eOverride
public stu handle(Resultset) throws SQLException
TODO Auto-generated method otub
return null;
/执行 query()方法,需要给出结果集处理器,即 ResultsetHandler 的实现类对象
/我们给的是 BeanHandler,它实现了 ReaultsetHandler
它需要一个类型,然后它会把中的数据封装到指定类型的 iavabean 对象中,然后返回 avabea
stu stu. query(, new BeanHandler(stu. class), params):
8yatem.out.printIn(atu);
aTest
publie void fun3() throws Exception
QueryRunner gr new QueryRunner(JdbcUtila.getDataSource()
string sql ="select from t stu";
Liat atuliat qr. query(aql, new BeanLiatHandler(stu.class))
syatem. out. printIn (atuliat)
@Test
publia void fun3() throws Exception
QueryRunner qr new QueryRunner(Jdbeutils. getDataSource()
string aql ="aelect from t atu":
List stuList qr.query (aql, new BeantistHandler(.olass))
Syatem.out.printIn()
/
MapHandler 的应用,它是单行处理器,把一行转换成一个 ap 对象 ethrowa SQLException
/
public void fun4() throws SQLException
QueryRunner gr new QueryRunner (JdbeUtils. getDataSource()
String agl =" from t atu where id=?";
object[] params =(1001):
Map map qr. query(, new MapHandler () parama);
Syatem.out. println(map)
ava. stuav
public void funi()throws SQmException
QueryRunner qr new QueryRunner(Jdbeutils. getDatasource()
string agl "aelect from t atu where aid=?":
object[] params ={10011:
Map map qr.query (ag1, new MapHandler(), parama):
System. out. printIn(map)
】/
MapLiatHandler,它是多行处理器把每行都转换成一个 Map ,即 iat
throws SQLException
QTest
public void fun5() throws SQLException
QueryRunner gr new QueryRunrJdlbcUtila. getDataSo
string sql "select from t atu";
Liat mapLiat qr. qughy (agl, new MapLiatHandler ()
Syatem. out. printIn(maptiat)
publie void fun5() throws SQLException
QueryRunner qr new QueryRunnerJdbcUtila. gotDataSource())
string sql "select from t_stu";
List> maplist. query(, new MapLiatHandler (
system.out.printIn(mapList)
8calarHandler,它是单行单列时使用,最为合适
9throws SQLException
@Test
public void fun6() throws SQLException
QueryRunner gr new QueryRunner(JdbcUtils. getDataSource()
string sql "select count (* from tatu";
object obj. query (aql new SealarHandler()
Syatem.out.printIn(obj)
