Mysql return more than one row - mysql

Question

I have this query.
SELECT notes.id,enter.name as 'enter_name',step.title as 'flow status',notes.user_name as user_created,notes.created,notes.rel_client_id,td_doc_nr.value_string as 'document number',enter.enter_code,
IF(!ISNULL(td_doc_nr.value_string),
(SELECT GROUP_CONCAT(product_name SEPARATOR ',') from notes d
join note_bundles b on b.note_id = d.id
join note_products p on p.doc_bundle_id = b.id
join note_product_get_fields f on f.doc_product_id = p.id
join note_product_get_field_data fd on fd.get_field_id = f.id
where d.doc_nr = td_doc_nr.value_string
and value_string ='auto')
,NULL) as test
FROM notes notes
JOIN notes_steps step ON step.id = notes.step_id
JOIN notes_enters enter ON enter.id = notes.enter_id
LEFT JOIN notes_custom_fields tf_doc_nr ON tf_doc_nr.name = 'note_number' AND tf_doc_nr.rel_entity_id = enter.id
LEFT JOIN notes_custom_field_data td_doc_nr ON td_doc_nr.rel_entity_id = notes.id AND
td_doc_nr.field_instance_id = tf_doc_nr.id
WHERE notes.enter_id in (777) AND notes.status = 1
I added this subquery to the 'if statement'
SELECT GROUP_CONCAT(product_name SEPARATOR ',') from nontes d
join note_bundles b on b.note_id = d.id
join note_products p on p.doc_bundle_id = b.id
join note_product_get_fields f on f.doc_product_id = p.id
join note_product_get_field_data fd on fd.get_field_id = f.id
where d.doc_nr = 'G7777777'
and value_string ='auto'
After this I added a new column.
SELECT GROUP_CONCAT(product_name SEPARATOR ','),GROUP_CONCAT(DISTINCT b.msisdn SEPARATOR ',') from notes d
join note_bundles b on b.note_id = d.id
join note_products p on p.doc_bundle_id = b.id
join note_product_get_fields f on f.doc_product_id = p.id
join note_product_get_field_data fd on fd.get_field_id = f.id
where d.doc_nr = 'G7777777'
and value_string ='auto'
It returns two columns.
How can I return two columns?Is it possible? :) Thanks

Answer 1

A subquery inside an IF statement can't return multiple columns. You will need to join the subquery into the results, and pull out the two separate columns individually:
SELECT ...
IF(!ISNULL(td_doc_nr.value_string), sub.one, NULL) as one,
IF(!ISNULL(td_doc_nr.value_string), sub.two, NULL) as two
FROM ...
LEFT JOIN (
SELECT d.doc_nr, GROUP_CONCAT(product_name SEPARATOR ','),GROUP_CONCAT(DISTINCT b.msisdn SEPARATOR ',') from documents d
join document_bundles b on b.document_id = d.id
join document_products p on p.doc_bundle_id = b.id
join document_product_cstm_fields f on f.doc_product_id = p.id
join document_product_cstm_field_data fd on fd.cstm_field_id = f.id
where value_string ='auto'
group by d.doc_nr
) sub on sub.doc_nr = td_doc_nr.value_string

Answer 2

A correlated subquery inside an IF statement can only return 1 column and 1 row, this is why you are getting the error. However, looking over your query the only outer reference inside the subquery is
d.doc_nr = td_doc_nr.value_string
So you do not need actually need a correlated subquery and you can achieve the same result by moving the subquery to a join and grouping by doc_nr within the subquery, which will probably be much more efficient, and it will allow you to return the 2 columns you want:
SELECT tickets.id,
source.name as 'source_name',
flow_stage.title as 'flow status',
tickets.user_name as user_created,
tickets.created,
tickets.rel_client_id,
td_doc_nr.value_string as 'document number',
source.source_code,
IF(!ISNULL(td_doc_nr.value_string), ProductNames, NULL) as test,
d.MSISDNS
FROM tickets tickets
JOIN tickets_flow_stages flow_stage
ON flow_stage.id = tickets.flow_stage_id
JOIN tickets_sources source
ON source.id = tickets.source_id
LEFT JOIN tickets_custom_fields tf_doc_nr
ON tf_doc_nr.name = 'document_number'
AND tf_doc_nr.rel_entity_id = source.id
LEFT JOIN tickets_custom_field_data td_doc_nr
ON td_doc_nr.rel_entity_id = tickets.id
AND td_doc_nr.field_instance_id = tf_doc_nr.id
LEFT JOIN
( SELECT d.Doc_nr,
GROUP_CONCAT(product_name SEPARATOR ',') AS ProductNames,
GROUP_CONCAT(DISTINCT b.msisdn SEPARATOR ',') AS MSISDNS
from documents d
INNER JOIN document_bundles b
ON b.document_id = d.id
INNER JOIN document_products p
ON p.doc_bundle_id = b.id
INNER JOIN document_product_cstm_fields f
ON f.doc_product_id = p.id
INNER JOIN document_product_cstm_field_data fd
ON fd.cstm_field_id = f.id
WHERE value_string ='auto'
GROUP BY d.Doc_nr
) d
ON d.doc_nr = td_doc_nr.value_string
WHERE tickets.source_id IN (114,122,125,129,131)
AND tickets.status = 1