1、@Select
这个是按条件查询的使用
@Select({"<script>", "select * from user ", "where 1=1", "<when test='userName != null and userName != \"\"'>", " AND user_name = #{userName}", "</when>",
"<when test='userPhone != null and userPhone != \"\"'>", " AND user_phone = #{userPhone}", "</when>", "</script>"})
List<UserInfo> getMerchantOrderList(UserModel userModel);
2、@Update
这个是不确定修改那些字段
@Update({"<script>", "update user", "<set>", "<if test='userName != null'>", "user_name = #{userName},", "</if>",
"<if test='password !=null'>", "password = #{password},", "</if>", "</set>", "where user_id = #{userId}", "</script>"})
void updateUserInfo(UserInfo userInfo);
3、@Insert
这个是数据库自动生成user_id,可以把插入的这条数据的user_id返回到你传参的实体类对应的字段中
@Insert("insert into user(user_name,password) values(#{userName}, #{password})")
@Options(useGeneratedKeys = true, keyProperty = "userId", keyColumn = "user_id")
void insertUser(UserInfo userInfo);