Home/ Questions/Q 8420473
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-10T02:53:35+00:00

Here is the case: There is a user table id email orders_counter ================================= 1

  • 0

Here is the case:

There is a user table

id     email      orders_counter
=================================
1      a@a.com    5
2      b@b.com    3
3      c@c.com    0

And a user data table for user’s other data

id     user_id      title      value
=======================================
1      1            Name       Peter Johnson
2      1            Tel        31546988
3      2            Name       Alan Johnson
4      2            Tel        56984887

If I want to fetch all user that

1, orders_counter greater then 3
2, Name contain 'Johnson'
3, Tel contain '88'

AT THE SAME TIME

What is my sql, and if I want to do it rubyonrails way
what is the ActiveRecord code
I know I can it one by one and then join all of them together, but it waste too much resource while conditions build up

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team
    Select * From `user` u
inner join `userdata` d on d.user_id=u.id and d.title='Name' and d.value like '%Johnson%'
inner join `userdata` c on c.user_id=u.id and c.title='Tel' and c.value like '%88%'
where orders_counter > 3

    the way that you’ve got your user data table structured, you’ll almost always have to join on that table several times in order to “pivot” those values into columns. I’d recommend just creating a table that has name and tel as columns. then the query becomes a lot more simple

    select * from `user` u
inner join `user_data` d on d.Tel like '%88%' and d.Name like '%johnson%'
where u.orders_counter > 3
    • 0