标签:多条件 sql use delete 执行 values gen 标签 day
MyBatis注解开发
@Insert注解
注解属性value:写入SQL语句
@Options注解
实现添加新数据的主键封装
注解属性
useGeneratedKeys:使用生成的主键,配置为true
keyProperty:主键封装的pojo对象属性
@SelectKey注解
实现添加新数据的主键封装
注解属性
statement:要执行的SQL语句
before:在添加SQL语句之前还是之后进行,配置为false
keyProperty:主键封装的pojo对象属性
注解实现添加数据
UserMapper接口
//新增用户数据 @Insert("insert into user(username,sex,birthday,address)values(# {username},#{sex},#{birthday},#{address})") void saveUser(User user);
UserMapper测试
/** * 注解开发 * 添加用户数据 */ @Test public void testSaveUser(){ SqlSession sqlSession = sqlSessionFactory.openSession(); User user = new User(); user.setUsername("孙权"); user.setSex("1"); user.setBirthday(new Date()); user.setAddress("东吴"); UserMapper userMapper = sqlSession.getMapper(UserMapper.class); userMapper.saveUser(user); sqlSession.commit(); System.out.println(user); sqlSession.close(); }
@Update注解
注解属性value:写入SQL语句
注解实现更新数据
UserMapper接口
//跟新用户 @Update("update user set username=#{username},sex=#{sex},birthday=# {birthday},address=#{address} where id=#{id}") void updateUser(User user);
UserMapper测试
/** * 注解开发 * 更新用户数据 */ @Test public void testUpdateUser(){ SqlSession sqlSession = sqlSessionFactory.openSession(); User user = new User(); user.setId(21); user.setUsername("孙策"); user.setSex("2"); user.setBirthday(new Date()); user.setAddress("江东"); UserMapper userMapper = sqlSession.getMapper(UserMapper.class); userMapper.updateUser(user); sqlSession.commit(); sqlSession.close(); }
@Delete注解
注解属性value:写入SQL语句
注解实现删除数据
UserMapper接口
//删除用户 @Delete("delete from user where id = #{id}") void deleteUser(int id);
UserMapper测试
/** * 注解开发 * 更新用户数据 */ @Test public void testDeleteUser(){ SqlSession sqlSession = sqlSessionFactory.openSession(); UserMapper userMapper = sqlSession.getMapper(UserMapper.class); userMapper.deleteUser(21); sqlSession.commit(); sqlSession.close(); }
@Select注解
注解属性value:写入SQL语句
注解实现主键查询用户数据
UserMapper接口
//主键查询用户 @Select("select id,username,sex,birthday,address from user where id = #{id}") User queryUserById(int id);
UserMapper测试
/** * 注解开发 * 主键查询用户 */ @Test public void testQueryUserById(){ SqlSession sqlSession = sqlSessionFactory.openSession(); UserMapper userMapper = sqlSession.getMapper(UserMapper.class); User user = userMapper.queryUserById(1); System.out.println(user); sqlSession.close(); }
注解实现查询全部用户数据
UserMapper接口
//查询全部用户 @Select("select id,username,sex,birthday,address from user") List<User> queryUserByList();
UserMapper测试
/** * 注解开发 * 查询全部用户 */ @Test public void testQueryUserByList(){ SqlSession sqlSession = sqlSessionFactory.openSession(); UserMapper userMapper = sqlSession.getMapper(UserMapper.class); List<User> userList = userMapper.queryUserByList(); if (userList != null && userList.size() > 0){ for (User user : userList){ System.out.println(user); } } sqlSession.close(); }
动态SQL语句之where和if
UserMapper接口
//多条件查询用户 @Select("<script>select id,username,sex,birthday,address from user" + "<where>" + "<if test = \"sex != null and sex != ‘‘\">" + " and sex = #{sex}" + "</if>" + "<if test = \"username != null and username != ‘‘\">" + " and username like #{username}" + "</if>" + "</where></script>") List<User> queryUserByWhere(User user);
UserMapper测试
/** * 注解开发 * 多条件查询用户信息 */ @Test public void testQueryUserByWhere(){ SqlSession sqlSession = sqlSessionFactory.openSession(); UserMapper userMapper = sqlSession.getMapper(UserMapper.class); User user = new User(); user.setSex("2"); user.setUsername("%王%"); List<User> userList = userMapper.queryUserByWhere(user); if(userList != null && userList.size() > 0){ for(User user1 : userList){ System.out.println(user1); } } sqlSession.close(); }
动态SQL语句之foreach
UserMapper接口
@Select("<script>select id,username,sex,birthday,address from user" +
"<foreach collection = \"list\" open = \"where id in(\" close
= \")\" separator = \",\" item = \"item\">" +
"#{item}" +
"</foreach>" +
"</script>")
List<User> queryUserByListIds(List<Integer> ids);
UserMapper测试
/** * 注解开发 * 传入List集合,查询用户数据 */ @Test public void testQueryUserByListIds(){ SqlSession sqlSession = sqlSessionFactory.openSession(); UserMapper userMapper = sqlSession.getMapper(UserMapper.class); List<Integer> ids = new ArrayList<Integer>(); ids.add(1); ids.add(2); ids.add(3); List<User> userList = userMapper.queryUserByListIds(ids); if(userList != null && userList.size() > 0){ for(User user : userList){ System.out.println(user); } } sqlSession.close(); }
一对一的注解开发
@Results注解
配置手动映射,取代resultMap标签
@Result注解
配置手动映射,取代result标签
OrdersMapper接口
//根据订单查询用户,一对一查询 @Select(" SELECT o.id,o.user_id,o.number,o.createtime,o.note FROM orders o") @Results({ //配置主键映射,id默认false,不是主键 @Result(id = true,column = "id",property = "id"), //配置其他映射关系 @Result(column = "user_id",property = "userId"), @Result(column = "number",property = "number"), @Result(column = "createtime",property = "createtime"), @Result(column = "note",property = "note"), /* 配置关联查询用户表 property查询的pojo对象哪个属性做为条件查询 这个属性还是个pojo对象 column查询条件的pojo对象的属性 @One注解配置一对一的另一个查询语句 此语句需要对应的接口方法出现 */ @Result(column = "user_id",property = "user",javaType = User.class, one = @One(select = "com.itheima.mapper.UserMapper.queryUserByUserId",fetchType = FetchType.LAZY)) }) List<Orders> queryOrdersUser();
UserMapper接口
@Select("select id,username,sex,birthday,address from user where id=# {user_Id}") User queryUserByUserId(Integer id);
OrdersMapp接口测试
/** * 注解开发 * 一对一延迟加载测试 */ @Test public void testQueryOrdersUser(){ SqlSession sqlSession = sqlSessionFactory.openSession(); OrdersMapper ordersMapper = sqlSession.getMapper(OrdersMapper.class); List<Orders> ordersList = ordersMapper.queryOrdersUser(); if(ordersList != null && ordersList.size() > 0){ for(Orders orders : ordersList){ System.out.println(orders); System.out.println(orders.getUser()); } } sqlSession.close(); }
一对多注解开发
UserMapper接口
//用户查询订单,一对多 @Select("select id,username,sex,birthday,address from user") @Results({ @Result(id = true,column = "id",property = "id"), @Result(column = "username",property ="username" ), @Result(column = "sex",property ="sex" ), @Result(column = "birthday",property ="birthday" ), @Result(column = "address",property ="address" ), @Result(column = "id",property = "ordersList",javaType = List.class, many = @Many(select = "com.itheima.mapper.OrdersMapper.queryOrdersByUserId",fetchType = FetchType.LAZY)) }) List<User> queryUserOrders();
OrdersMapper接口
//用户查询订单,一对多 @Select("select number,createtime from orders where user_id = # {user_id}" ) List<Orders> queryOrdersByUserId(Integer user_id);
UserMapper接口测试
/** * 注解开发 * 查询用户下的订单,一对多 */ @Test public void testQueryUserOrders(){ SqlSession sqlSession = sqlSessionFactory.openSession(); UserMapper userMapper = sqlSession.getMapper(UserMapper.class); List<User> userList = userMapper.queryUserOrders(); if(userList != null && userList.size() > 0){ for(User user : userList){ System.out.println(user); System.out.println(user.getOrdersList()); } } sqlSession.close(); }
标签:多条件 sql use delete 执行 values gen 标签 day
原文地址:https://www.cnblogs.com/qingmuchuanqi48/p/10920923.html