a 表字段
id
name
b_id
c_id
b表字段id
name
c_idc表字段id
name
关系是:select id, b.name, c.name from a
left join b on a.b_id = b.id
left join c on a.c_id = c.id
where id = 1
order id desc
当然,上面那个sql语句会报错。。我有没有办法,通过其他的设,让
select id, b.name, c.name from a
left join b on a.b_id = b.id
left join c on a.c_id = c.id
where id = 1
order id desc这里的id 默认取 主表 a 里的id
id
name
b_id
c_id
b表字段id
name
c_idc表字段id
name
关系是:select id, b.name, c.name from a
left join b on a.b_id = b.id
left join c on a.c_id = c.id
where id = 1
order id desc
当然,上面那个sql语句会报错。。我有没有办法,通过其他的设,让
select id, b.name, c.name from a
left join b on a.b_id = b.id
left join c on a.c_id = c.id
where id = 1
order id desc这里的id 默认取 主表 a 里的id
select a.id, b.name, c.name from b
right join a on a.b_id = b.id
left join c on a.c_id = c.id
where a.id = 1
order by a.id desc
left join b on a.b_id = b.id
left join c on a.c_id = c.id
where a.id = 1
order a.id desc