BigQuery select multiple tables with different column names - google-bigquery

Question

Consider the following BigQuery tables schemas in my dataset my_dataset:
Table_0001: NAME (string); NUMBER (string)
Table_0002: NAME(string); NUMBER (string)
Table_0003: NAME(string); NUMBER (string)
...
Table_0865: NAME (string); CODE (string)
Table_0866: NAME(string); CODE (string)
...
I now want to union all tables using :
select * from `my_dataset.*`
However this will not yield the CODE column of the second set of table. From my understanding, the schema of the first table in the dataset will be adopted instead.
So the result with be something like:
| NAME | NUMBER |
__________________
| John | 123456 |
| Mary | 123478 |
| ... | ...... |
| Abdul | null |
| Ariel | null |
I tried to tap into the INFORMATION_SCHEMA so as to select the two sets of tables separately and then union them:
with t_code as (
select
table_name,
from my_dataset.INFORMATION_SCHEMA.COLUMNS
where column_name = 'CODE'
),
select t.NAME, t.CODE as NUMBER from `my_dataset.*` as t
where _TABLE_SUFFIX in (select * from t_code)
However, still the script will look to the first table of my_dataset for its schema and will return: Error Running Query: Name CODE not found inside t.
So now I'm at a loss: How can I union all my tables without having to union them one by one? ie. how to select CODE as NUMBER in the second set of tables.
Note: Although it seems the question was asked over here, the accepted answer did not seem to actually respond to the question (as far as I'm concerned).

Answer 1

The trick I see you can do is to first gather all codes by running
create table `my_another_dataset.codes` as
select * from `my_dataset.*` where not code is null
Then to do any simple fake update of any just one table with number column - this will make schema with number column default. so now you can gather all numbers
create table `my_another_dataset.numbers` as
select * from `my_dataset.*` where not number is null
Finally then you can do simple union
select * from `my_another_dataset.numbers` union all
select * from `my_another_dataset.codes`
Note: see also my comment below your question

Answer 2

SELECT
borrow.id AS `borrowId`,
IF(borrow.created_date IS NULL, '', borrow.created_date) AS `borrowCreatedDate`,
IF(borrow.return_date IS NULL, '', borrow.return_date) AS `borrowReturnDate`,
IF(borrow.return_date IS NULL, '0', '1') AS `borrowIsReturn`,
IF(person.card_identity IS NULL, '', person.card_identity) AS `personCardIdentity`,
IF(person.fullname IS NULL, '', person.fullname) AS `personFullname`,
IF(person.phone_number IS NULL, '', person.phone_number) AS `personPhoneNumber`,
IF(book.book_name IS NULL, '', book.book_name) AS `bookName`,
IF(book.year IS NULL, '', book.year) AS `bookYear`
FROM tbl_tbl_borrow AS borrow
LEFT JOIN tbl_person AS person
ON person.card_identity = borrow.person_card_identity
LEFT JOIN tbl_book AS book
ON book.unique_id = borrow.book_unique_id
ORDER BY
borrow.return_date ASC, person.fullname ASC;