string_agg not behaving correctly

Question

I have table like this:

booking_id, state   
01          red      
01          green   
01          black   
02          red   
02          green   
03          red   

I wanted to get something like this:

01          red,green,black       
02          red,green      
03          red    

So I added string_agg function to my query, but the field ALLSTATES is returning a result like this:

01         red,red,red         
01         green,green,green           
01         black,black,black       
02         red,red        
02         green,green         
03         red   

   

This is my query:

SELECT bookings.id,
bookings.confirmed_at, 
bookings.disputed, 
bookings.no_show_claimed,
bookings.disputed_at,
bookings.no_show_blocked_until,
bookings.user_id,bookings.refunded,
bookings.refunded_at,invoices.id as invoice_id,
invoices.state,
invoices.currency_to_eur, 
max(lessons.time), 
greatest(max(lessons.time),
bookings.no_show_blocked_until,
bookings.confirmed_at), 
string_agg(',',invoices.state) as ALLSTATES


FROM bookings LEFT JOIN invoice_lines ON invoice_lines.booking_id = bookings.id 
LEFT JOIN invoices ON invoices.id = invoice_lines.invoice_id
 LEFT JOIN lesson_bookings ON lesson_bookings.booking_id = bookings.id 
LEFT JOIN lessons ON lessons.id = lesson_bookings.lesson_id 

GROUP BY (bookings.id,invoices.id)

any idea how to correct this please?

Answer 1

You seem to want:

string_agg(distinct invoices.state, ',') as ALLSTATES

You may also need to adjust the group by . However, your query is way more complicated than the sample data you have provided, so it is unclear exactly what changes are needed.