标签：一个 mes role 内容整理 false bat last HERE code
MyBatis除了支持XML方式以外，还支持注解方式，可将SQL语句直接写在接口上。
优点：对于需求比较简单的系统效率较高。
缺点：当SQL有变化时都需要重新编译代码。
1、基本用法
@Select({ "select id, role_name, enabled, create_by, create_time ", "from sys_role ", "where id = #{id}" }) SysRole selectById(Long id);
2、使用resultMap方式
@Results(id = "roleResultMap", value = { @Result(property = "id", column = "id", id = true), @Result(property = "roleName", column = "role_name"), @Result(property = "enabled", column = "enabled"), @Result(property = "createBy", column = "create_by"), @Result(property = "createTime", column = "create_time") }) @Select({ "select id, role_name, enabled, create_by, create_time ", "from sys_role ", "where id = #{id}" }) SysRole selectById2(Long id);
3、复用resultMap
当多个接口返回相同的resultMap时，无需再每一个接口方法上都添加@Results注解，可通过将待复用的resultMap添加id属性，然后在其他接口方法上通过id来指向通过一个引用，即可实现复用。
@ResultMap("roleResultMap")
@Select("select * from sys_role")
List<SysRole> selectAll();
1、不需要返回主键
@Insert({"insert into sys_role (id, role_name, enabled, create_by, create_time)",
"values (#{id}, #{roleName}, #{enabled}, #{createBy}, #{createTime, jdbcType=TIMESTAMP})"})
int insert(SysRole sysRole);
2、返回自增主键
@Insert({"insert into sys_role (role_name, enabled, create_by, create_time)",
"values (#{roleName}, #{enabled}, #{createBy}, #{createTime, jdbcType=TIMESTAMP})"})
@Options(useGeneratedKeys = true, keyProperty = "id")
int insert2(SysRole sysRole);
3、返回非自增主键
@Insert({"insert into sys_role (role_name, enabled, create_by, create_time)",
"values (#{roleName}, #{enabled}, #{createBy}, #{createTime, jdbcType=TIMESTAMP})"})
@SelectKey(statement = "SELECT LAST_INSERT_ID()",
keyProperty = "id",
resultType = Long.class,
before = false)
int insert3(SysRole sysRole);
@Update({"update sys_role",
"set role_name = #{roleName},",
"enabled = #{enabled},",
"create_by = #{createBy},",
"create_time = #{createTime, jdbcType=TIMESTAMP}",
"where id = #{id}"
})
int updateById(SysRole sysRole);
@Delete("delete from sys_role where id = #{id}")
int deleteById(Long id);
以上内容整理自《MyBatis从入门到精通》
标签：一个 mes role 内容整理 false bat last HERE code
原文地址：https://www.cnblogs.com/fantastic-clouds/p/13081446.html
