CODEWITHSUNDEEP
sqlgoogle-cloud-platformgoogle-bigquerylegacy-sql
user7463780
user7463780

Reputation:

Big Query - JOIN two tables

We have two tables like below:

Table A

 Name | Question  | Answer
 -----+-----------+-------
 Bob  | Interest  | art_and_theatre      
 Sue  | Interest  | finances_and_investments
 Sue  | Interest  | art_and_theatre
 Joe  | Interest  | cooking_and_nutrition
 Joe  | Interest  | nutrition_and_drinks
 Joe  | Interest  | eco_life
 Joe  | Interest  | beauty
 Bob  | Interest  | nutrition_and_drinks

Table B (Static)

           Interest                         |   Segment
--------------------------------------------+------------------
art_and_theatre                             |   S1
cooking_and_nutrition, nutrition_and_drinks |   S2 
finances_and_investments                    |   S3
finances_and_investments                    |   S4
technology                                  |   S5
telecommunications                          |   S6
art_and_theatre                             |   S7
art_and_theatre                             |   S8
eco_life, cooking_and_nutrition, beauty     |   S9

Expected table

 Name | Question  | Answer
 -----+-----------+-------
 Bob  | Interest  | art_and_theatre      
 Sue  | Interest  | finances_and_investments
 Sue  | Interest  | art_and_theatre
 Joe  | Interest  | cooking_and_nutrition
 Joe  | Interest  | nutrition_and_drinks 
 Bob  | Interest  | nutrition_and_drinks
          (+)
 Bob  | Segment   | S1
 Bob  | Segment   | S7
 Bob  | Segment   | S8
 Sue  | Segment   | S3
 Sue  | Segment   | S4
 Sue  | Segment   | S1
 Sue  | Segment   | S7
 Sue  | Segment   | S8
 Joe  | Segment   | S2
 Joe  | Segment   | S9

As you can see, one user can have multiple interests and multiple interests can belong to one segment. Is this kind of JOIN is possible in Big Query?

Note: The Interest column will have one or more values. Segments need to be joined only if all the values are matched.

Upvotes: 0

Views: 268

Answers (3)

Mikhail Berlyant
Mikhail Berlyant

Reputation: 172944

Below is for BigQuery Standard SQL

#standardSQL
select name, question, answer from `project.dataset.tableA`
union all
select distinct name, 'segment' as question, segment as answer
from (
  select answer, segment 
  from `project.dataset.tableB`, 
  unnest(split(interest, ', ')) answer
)
join `project.dataset.tableA`
using(answer)
-- order by question, name, answer

if to apply to sample data from your question - output is

enter image description here

Upvotes: 1

Daniel Zagales
Daniel Zagales

Reputation: 3034

Yes this is possible, you should be able to do it with the following SQL

with temp as (
   SELECT a.*, b.*
   FROM TABLEA a
   JOIN TABLEB b
    on a.answer = b.interest
)
SELECT t.Name, t.Question, t.Answer from temp
UNION ALL
SELECT t.Name, 'Segment' as Question, t.Segment as Answer from temp

Upvotes: 0

Gordon Linoff
Gordon Linoff

Reputation: 1269483

Hmmm . . . I'm thinking union all with a join:

select a.name, a.question, a.answer
from a
union all
select a.name, 'Segment', b.segment
from a join
     b
     on a.answer = b.interest;

Upvotes: 0

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