使用MyBatis注解开发，可以省去类配置文件，简洁方便。但是比较复杂的SQL和动态SQL还是建议书写类配置文件。

注解还是不推荐使用的。只是了解了解！

简单的CRUD可以使用注解。简单写写。

    把之前的例子改成使用注解的。

 

UserMapper.java

 

1 package com.cy.mybatis.mapper;  2   3 import java.util.List;  4 import java.util.Map;  5   6 import org.apache.ibatis.annotations.Delete;  7 import org.apache.ibatis.annotations.Insert;  8 import org.apache.ibatis.annotations.Options;  9 import org.apache.ibatis.annotations.Param; 10 import org.apache.ibatis.annotations.Result; 11 import org.apache.ibatis.annotations.ResultMap; 12 import org.apache.ibatis.annotations.Results; 13 import org.apache.ibatis.annotations.Select; 14 import org.apache.ibatis.annotations.Update; 15  16 import com.cy.mybatis.beans.UserBean; 17  18 public interface UserMapper { 19     // 简单的增删改查可以使用注解 20     // 注解+配置文件 21      22     /** 23      * 新增用戶 24      * @param user 25      * @return 26      * @throws Exception 27      */ 28     @Insert("insert into t_user value (null,user.username,user.password,user.account)") 29     @Options(useGeneratedKeys=true,keyProperty="user.id") 30     public int insertUser(@Param("user")UserBean user) throws Exception; 31      32      33     /** 34      * 修改用戶 35      * @param user 36      * @param id 37      * @return 38      * @throws Exception 39      */ 40     @Update(" update t_user set username=#{u.username},password=#{u.password},account=#{u.account} where id=#{id}") 41     public int updateUser (@Param("u")UserBean user,@Param("id")int id) throws Exception; 42      43      /** 44       * 刪除用戶 45       * @param id 46       * @return 47       * @throws Exception 48       */ 49     @Delete(" delete from t_user where id=#{id}  ") 50     public int deleteUser(int id) throws Exception; 51      52      53     /** 54      * 根据id查询用户信息 55      * @param id 56      * @return 57      * @throws Exception 58      */ 59      60     @Select(" select * from t_user where id=#{id}") 61     @Results({ 62          63         @Result(id=true,property="id",column="id",javaType=Integer.class), 64         @Result(property="username",column="username",javaType=String.class), 65         @Result(property="password",column="password",javaType=String.class), 66         @Result(property="account",column="account",javaType=Double.class) 67     }) 68     public UserBean selectUserById(int id) throws Exception; 69      /** 70       * 查询所有的用户信息 71       * @return 72       * @throws Exception 73       */ 74      75     @Select(" select * from t_user") 76     @ResultMap("userMap") 77     public List
      
        selectAllUser() throws Exception; 78      79      80     /** 81      * 批量增加 82      * @param user 83      * @return 84      * @throws Exception 85      */ 86    public int batchInsertUser(@Param("users")List
       
         user) throws Exception; 87     88    /** 89     * 批量删除 90     * @param list 91     * @return 92     * @throws Exception 93     */ 94    public int batchDeleteUser(@Param("list")List
        
          list) throws Exception; 95     96     97    /** 98     * 分页查询数据 99     * @param parma100     * @return101     * @throws Exception102     */103    public List
         
           pagerUser(Map
          
            parmas) throws Exception;104    105    /**106     * 107     * 分页统计数据108     * @param parma109     * @return110     * @throws Exception111     */112     public int countUser(Map
           
             parmas) throws Exception; 113 114 }
           
          
         
        
       
      

 UserMapper.xml

 

1 
       2  3 
      
        4 
        5    
       
         6         
         7         
         8         
         9         
        10     
       11     12     
       13     14     
       
        15        insert into t_user values 16         
        
         17          (null,#{users.username},#{users.password},#{users.account})18         
        19     
       20     21     22     
       
        23        delete from t_user where id in (24          
        
         25           #{id}26          
        27        )28     
       29     30     
       31     
       32     
       33     34     
       37     
       38       select * from t_user where 1=139       40        and username like '%${username}%'41       42        limit ${index},${pageSize} 43     44     45     
       46         select count(*) from t_user where 1=1 47         48             and username like '%${username}%'    49         50         51     52 
      

 

 简单的一个一对一的使用注解的。

1 package com.lovo.mybatis.mapper; 2  3 import org.apache.ibatis.annotations.Insert; 4 import org.apache.ibatis.annotations.One; 5 import org.apache.ibatis.annotations.Options; 6 import org.apache.ibatis.annotations.Param; 7 import org.apache.ibatis.annotations.Result; 8 import org.apache.ibatis.annotations.ResultType; 9 import org.apache.ibatis.annotations.Results;10 import org.apache.ibatis.annotations.Select;11 12 import com.lovo.mybatis.beans.HusbandBean;13 import com.lovo.mybatis.beans.WifeBean;14 15 public interface HusbandMapper {16     17     /**18      * 保存丈夫19      * @param husband20      * @return21      */22     @Insert("insert into t_husband values (null,#{h.name})")23     @Options(useGeneratedKeys=true,keyProperty="h.id")24     public int saveHusband(@Param("h")HusbandBean husband);25     26     27     /**28      * 根据ID查询丈夫资料29      * @param id30      * @return31      */32     @Select("select * from t_husband where id=#{id}")33     @ResultType(HusbandBean.class)34     public HusbandBean findHusbandById(int id);35     36     37     38     /**39      * 根据ID查询丈夫与妻子资料40      * @param id41      * @return42      */43     @Select("select * from t_husband where id=#{id}")44     @Results({45         @Result(id=true,property="id",column="id",javaType=Integer.class),46         @Result(property="name",column="name",javaType=String.class),47         @Result(property="wife",column="id",javaType=WifeBean.class,one=@One(select="com.lovo.mybatis.mapper.WifeMapper.findWifeByHusbandId"))48     })49     public HusbandBean findHusbandAndWife(int id);50     51     52 }

 

1 package com.cy.mybatis.mapper; 2  3 import org.apache.ibatis.annotations.ResultType; 4 import org.apache.ibatis.annotations.Select; 5  6 import com.cy.mybatis.beans.WifeBean; 7  8 public interface WifeMapper { 9     10     11     @Select("select * from t_wife where fk_husband_id = #{id}")12     @ResultType(WifeBean.class)13     public WifeBean selectWifeByHusbandId(int id)throws Exception;14 15 }

 注意：使用resultType时，一定要保证，你属性名与字段名相同；如果不相同，就使用resultMap 。