表1:task_table
字段为:task_id
creat_user_id
check_user_id
表2:user_table
字段为:user_id
user_name现在想查询task_id为'1002'的记录,同时查询该记录中creat_user_id对应的user_name和check_user_id对应的user_name请问这个SQL语句该怎么写
字段为:task_id
creat_user_id
check_user_id
表2:user_table
字段为:user_id
user_name现在想查询task_id为'1002'的记录,同时查询该记录中creat_user_id对应的user_name和check_user_id对应的user_name请问这个SQL语句该怎么写
a.*
from user_table a join task_table b on a.user_id in(b.creat_user_id ,b.check_user_id)
select a.user_name ,b.user_name from 表1 inner join 表2 a on 表1.creat_user_id=a.user_name inner join 表2 b on 表1.check_user_id=b.user_name where 表1.task_id='1002'
select a.user_name ,b.user_name from 表1 inner join 表2 a on 表1.creat_user_id=a.user_id inner join 表2 b on 表1.check_user_id=b.user_id where 表1.task_id='1002'
task_id creat_user_name check_user_name
1002 张三 李四
select
b.user_name ,c.user_name
from
task_table a
join
user_table b on a.creat_user_id =b.user_id
join
user_table c on a.check_user_id=c.user_id
a.task_id,b. user_name,c. user_name
from task_table a join user_table b on a.creat_user_id=b.user_id
join user_table c on a.check_user_id=b.user_id
where task_id="1002"
或者:
select
task_id,b. user_name,c. user_name
from task_table,user_table a,user_table b
where creat_user_id=a.user_id and
check_user_id=b.user_id and
task_id="1002"