private ComboPooledDataSource dataSource = new ComboPooledDataSource();
@Test public void testArrayHandler() throws SQLException{ //ArrayHandler 将结果集的第一行数据存入Object数组 QueryRunner queryRunner = new QueryRunner(dataSource); String sql = "select * from account"; //数组的每一个元素对应第一行数据的每一列 Object[] objects = queryRunner.query(sql, new ArrayHandler()); System.out.println(Arrays.toString(objects)); }
@Test public void testArrayListHandler() throws SQLException{ //ArrayListHandler 将结果集的每一行数据存入Object数组,然后存入List QueryRunner queryRunner = new QueryRunner(dataSource); String sql = "select * from account"; Listnew ArrayListHandler()); for(Object[] objects : list){ System.out.println(Arrays.toString(objects)); } }
@Test public void testBeanHandler() throws SQLException{ //BeanHandler 将结果集的第一行数据封装到JavaBean对象中 QueryRunner queryRunner = new QueryRunner(dataSource); String sql = "select * from account"; //传入Account.class参数是为了在方法中通过反射构造Account对象实例 Account account = queryRunner.query(sql, new BeanHandler
@Test public void testBeanListHandler() throws SQLException{ //BeanListHandler 将结果集每一条数据都封装到JavaBean对象,再存入List QueryRunner queryRunner = new QueryRunner(dataSource); String sql = "select * from account"; List
@Test public void testColumnListHandler() throws SQLException{ //ColumnListHandler 获得结果集的某一列 QueryRunner queryRunner = new QueryRunner(dataSource); String sql = "select * from account"; //泛型为什么写Object 因为每列的类型都不一样 Listnew ColumnListHandler("name")); System.out.println(list); }
@Test public void testMapHandler() throws SQLException{ //MapHandler 将结果集中的第一行数据封装到Map集合,key是列名,value是数据值 QueryRunner queryRunner = new QueryRunner(dataSource); String sql = "select * from account"; Map
@Test public void testMapListHandler() throws SQLException { // MapHandler 将结果集中的每一行数据封装到Map集合,key是列名,value是数据值,再将Map对象存入List QueryRunner queryRunner = new QueryRunner(dataSource); String sql = "select * from account"; Listnew MapListHandler()); for(Map
@Test public void testKeyedHandler() throws SQLException { // KeyedHandler 将结果集中的每一行数据都封装到Map里,再将Map存入一个Map里,key可以指定为任意列 QueryRunner queryRunner = new QueryRunner(dataSource); String sql = "select * from account"; Mapnew KeyedHandler("name")); System.out.println(map); }
@Test public void testScalarHandler() throws SQLException{ //ScalarHandler 通常保存只有一行一列的结果数据 QueryRunner queryRunner = new QueryRunner(dataSource); String sql = "select count(*) from account"; long count = (Long) queryRunner.query(sql, new ScalarHandler(1)); System.out.println(count); }
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