Question

create table role (
  role varchar(20),
  id int
);

insert into role (role, id) values ('Friend', 1);
insert into role (role, id) values ('Son', 2);
insert into role (role, id) values ('Daughter', 3);
insert into role (role, id) values ('Father', 4);
insert into role (role, id) values ('Mother', 5);
insert into role (role, id) values ('Brother', 6);
insert into role (role, id) values ('Sister', 7);

create table person (
  persons varchar(20),
  personid int
);

insert into person (persons, personid) values ('James', 1);
insert into person (persons, personid) values ('Peter', 2);
insert into person (persons, personid) values ('Joseph', 3);
insert into person (persons, personid) values ('Jeni', 4);

create table role_person (
  roleid int,
  personid int
);

insert into role_person (roleid, personid) values (2, 1);
insert into role_person (roleid, personid) values (2, 2);
insert into role_person (roleid, personid) values (4, 2);
insert into role_person (roleid, personid) values (6, 2);
insert into role_person (roleid, personid) values (6, 2);
insert into role_person (roleid, personid) values (3, 4);
insert into role_person (roleid, personid) values (4, 3);

我希望最终输出如下所示
final output

    persons  friend  son  daughter  father  mother  brother  sister
    James    -       Y    -         -       -       -        -
    Peter    -       Y    -         Y       -       Y        -
    Joseph   -       -    -         Y       -       -        -
    Jeni     -       -    Y         -       -       -        -

由于基础数据库是Maria DB，因此我无法使用数据透视功能。请注意，人们可以增加或减少/ 而且，明天的角色会像祖父，妻子等增加。

不确定在存储的proc或查询中如何解决此问题。

我们可以使用XML数据类型来处理动态查询。

Answer 1

那又怎么样：

select 
    p.persons,
    case when 1 in (select 1 from role_person rp where rp.personid = p.personid and rp.roleid = 1) then 'Y' else '-' end as friend,
    case when 1 in (select 1 from role_person rp where rp.personid = p.personid and rp.roleid = 2) then 'Y' else '-' end as son,
    case when 1 in (select 1 from role_person rp where rp.personid = p.personid and rp.roleid = 3) then 'Y' else '-' end as daughter,
    case when 1 in (select 1 from role_person rp where rp.personid = p.personid and rp.roleid = 4) then 'Y' else '-' end as father,
    case when 1 in (select 1 from role_person rp where rp.personid = p.personid and rp.roleid = 5) then 'Y' else '-' end as mother,
    case when 1 in (select 1 from role_person rp where rp.personid = p.personid and rp.roleid = 6) then 'Y' else '-' end as brother,
    case when 1 in (select 1 from role_person rp where rp.personid = p.personid and rp.roleid = 7) then 'Y' else '-' end as sister
  from person p;

结果：

persons  friend  son  daughter  father  mother  brother  sister
James    -       Y    -         -       -       -        -
Peter    -       Y    -         Y       -       Y        -
Joseph   -       -    -         Y       -       -        -
Jeni     -       -    Y         -       -       -        -

Answer 2

我认为到目前为止，无法在MariaDB中检索动态数目的列。

据我所知，此功能仅存在于：

Oracle（作为“模型”）。
PostgreSQL（作为“交叉表”）。
SQL Server（作为“枢轴”）。

Answer 3

我通过使用临时表，更改每个字段的临时表并使用正确的参数进行更新来解决此问题。

mariadb中复杂查询矩阵输出的需求解决方案

3 个答案: