DBUtils练习，增删改查，ResultSetHandler的9个结果处理器

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/** * DBUtils练习，增删改查，ResultSetHandler的9个结果处理器 */public class TestDBUtils {    @Test    public void testSelect() throws SQLException {        QueryRunner queryRunner = new QueryRunner(C3P0Util.getDataSource());        List<User> query = queryRunner.query("select * from user where password=?",                new BeanListHandler<User>(User.class), 321);        for (User u : query) {            System.out.println(u);        }    }    @Test    public void testInsert() throws SQLException {        QueryRunner queryRunner = new QueryRunner(C3P0Util.getDataSource());        queryRunner.update("insert into user(username,password,email,birthday) values(?,?,?,?)",                "老张", "123", "cx@qq.com", "2013-3-2");    }    @Test    public void testUpdate() throws SQLException {        QueryRunner queryRunner = new QueryRunner(C3P0Util.getDataSource());        queryRunner.update("update user set username=?,password=? where id=?",                "王婉婉", "321", 2);    }    @Test    public void testDelete() throws SQLException {        QueryRunner queryRunner = new QueryRunner(C3P0Util.getDataSource());        queryRunner.update("delete from user where id=?",                2);    }    @Test    public void testBatch() throws SQLException {        QueryRunner queryRunner = new QueryRunner(C3P0Util.getDataSource());        Object[][] objects = new Object[10][4];        for (int i = 0; i < objects.length; i++) {            objects[i][0] = "程啸" + i;            objects[i][1] = "aaa" + i;            objects[i][2] = i + "@q.c";            objects[i][3] = "2017-02-" + i;        }        queryRunner.batch("insert into user(username,password,email,birthday) values(?,?,?,?)", objects);    }    @Test//ArrayHandler适合取1条数据，把这条数据的每列值封装到一个数组中    public void test1() throws SQLException {        QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());        Object[] query = qr.query("select * from user where id=?", new ArrayHandler(), 13);        for (Object o : query)            System.out.println(o);    }    @Test//ArrayListHandler适合取多条数据，把这条数据的每列值封装到一个数组中，把数组封装到List中    public void test2() throws SQLException {        QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());        List<Object[]> query = qr.query("select * from user", new ArrayListHandler());        for (Object[] o : query) {            for (Object o1 : o)                System.out.print(o1);            System.out.println();        }    }    @Test//ColumnListHandler取某一列的数据，封装到List中    public void test3() throws SQLException {        QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());        List<Object> query = qr.query("select username,password from user", new ColumnListHandler<Object>(2));        for (Object u : query) {            System.out.println(u);        }    }    @Test//KeyedHandler:取多条数据，每一条记录封装到一个Map中，再把这个Map封装到另一个Map中，key为指定的字段值    public void test4() throws SQLException {        QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());        Map<Object, Map<String, Object>> query = qr.query("select id,username,password from user where username=?",                new KeyedHandler<Object>(1), "程啸2");        for (Map.Entry<Object, Map<String, Object>> entry : query.entrySet()) {            System.out.println(entry.getKey());            for (Map.Entry<String, Object> entry1 : entry.getValue().entrySet()) {                System.out.println(entry1.getKey() + "-->" + entry1.getValue());            }        }    }    @Test//MapHandler适合取1条数据，把当前记录的列名和列值放到一个Map中    public void test5() throws SQLException {        QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());        Map<String, Object> query = qr.query("select * from user where id=?", new MapHandler(), 22);        for (Map.Entry<String, Object> entry : query.entrySet())            System.out.println(entry.getKey() + ":" + entry.getValue());    }    @Test//MapListHandler:取多条数据，每一条记录封装到一个Map中，再把这个Map封装到List中    public void test6() throws SQLException {        QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());        List<Map<String, Object>> query = qr.query("select id,username,password from user where username=?",                new MapListHandler(), "程啸2");        for (Map<String, Object> map : query) {            for (Map.Entry<String, Object> entry : map.entrySet()) {                System.out.println(entry.getKey() + "-->" + entry.getValue());            }        }    }    @Test//ScalarHandler:适合取单行单列数据    public void test7() throws SQLException {        QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());        Object query = qr.query("select count(*) from user where username=?",                new ScalarHandler<Object>(1), "程啸2");        System.out.println(query.getClass().getName());    }    @Test//BeanHandler:适合取单条数据，并返回一个对象    public void test8() throws SQLException {        QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());        Object query = qr.query("select * from user where username=?",                new BeanHandler<User>(User.class), "程啸2");        System.out.println(query);    }    @Test//BeanListHandler:适合取多行数据，并返回对象List    public void test9() throws SQLException {        QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());        List<User> list = qr.query("select * from user where username=?",                new BeanListHandler<User>(User.class), "程啸2");        for (User u:list) {            System.out.println(u);        }    }}
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