Mybatis注解使用
@Select注解
可以在接口方法上使用,也可以在xml文件中使用;使用@Select注解需要在注解中指定sql语句
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| @Mapper
public interface TeacherMapper extends BaseMapper<TeacherEntity> {
@Select("select id,sys_name name from sys_teacher")
List<TeacherEntity> getList();
}
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@Insert注解
同上
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| @Mapper
public interface TeacherMapper extends BaseMapper<TeacherEntity> {
@Insert("insert into sys_teacher(sys_name,sys_age) value('张三',18)")
boolean saveEntity();
}
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@Update注解
同上
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| @Mapper
public interface TeacherMapper extends BaseMapper<TeacherEntity> {
@Update("update sys_teacher set sys_name = '李四', sys_age = 22 where id = 8 ")
int updateEntity();
}
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@Delete注解
同上
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| @Mapper
public interface TeacherMapper extends BaseMapper<TeacherEntity> {
@Delete("delete from sys_teacher where id = #{id}")
boolean deleteEntity(Integer id);
}
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@Result注解
同上;用于标记单个属性与结果集中的列之间的映射关系,通常与@Results注解搭配使用
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| @Mapper
public interface TeacherMapper extends BaseMapper<TeacherEntity> {
@Select("select sys_name , sys_age from sys_teacher where id = #{id}")
@Result(property = "name", column = "sys_name")
@Result(property = "sysAge", column = "sys_age")
TeacherEntity getEntityById(Integer id);
}
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@Results注解
用于指定多个@Result注解
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| @Mapper
public interface TeacherMapper extends BaseMapper<TeacherEntity> {
@Select("select * from sys_teacher where id = #{id}")
@Results(id = "teacherResultMap", value = {
@Result(property = "name", column = "sys_name")
})
TeacherEntity getEntityByIdWithResultsAnnotation(Integer id);
}
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