create a table with a column type RECORD - google-bigquery

Question

I'm using big query and i want to create a job which populates a table with a "record" type columns.
The data will be populated by a query - so how can i write a query which returns "record" type columns.
Thanks!

Answer 1

Somehow option proposed by Pentium10 never worked for me in GBQ UI or API Explorer.
I might be missing something
Meantime, the workaround I found is as in below example
SELECT location.state, location.city FROM JS(
( // input table
SELECT NEST(CONCAT(state, ',', city)) AS locations
FROM (
SELECT state, city FROM
(SELECT 'florida' AS state, 'miami' AS city),
(SELECT 'california' AS state, 'la' AS city),
(SELECT 'romania' AS state, 'transylvania' AS city)
)
),
locations, // input columns
"[ // output schema
{'name': 'location', 'type': 'RECORD',
'mode': 'REPEATED',
'fields': [
{'name': 'state', 'type': 'STRING'},
{'name': 'city', 'type': 'STRING'}
]
}
]",
"function(row, emit){ // function
for (var i = 0; i < row.locations.length; i++) {
var c = [];
x = row.locations[i].split(',');
t = {state:x[0], city:x[1]}
c.push(t);
emit({location: c});
};
}"
)
Please note:
you should set destination table with Allow Large Results and unchecked Flatten Results
Result from output table is (in JSON Mode)
[
{
"location": [
{
"state": "california",
"city": "la"
}
]
},
{
"location": [
{
"state": "florida",
"city": "miami"
}
]
},
{
"location": [
{
"state": "romania",
"city": "transylvania"
}
]
}
]
Added to address some issue #AdiCohen has with his real example that
he showed in his recent comments:
Q: my query has other columns besides the record column, but when i ran
the query, they return as null. how can i create a table with both of
the types?
SELECT amount, currency, location.state, location.city FROM JS(
( // input table
SELECT NEST(CONCAT(state, ',', city)) AS locations,
SUM(amount) AS amount, MAX(currency) as currency
FROM (
SELECT state, city, amount, currency, ROW_NUMBER() OVER() as grp FROM
(SELECT 'florida' AS state, 'miami' AS city, 'coins' AS currency, 40 AS amount),
(SELECT 'california' AS state, 'la' AS city, 'coins' AS currency, 40 AS amount),
(SELECT 'romania' AS state, 'transylvania' AS city,'coins' AS currency, 40 AS amount)
) GROUP BY grp
),
amount, currency, locations, // input columns
"[ // output schema
{'name': 'location', 'type': 'RECORD', 'mode': 'REPEATED',
'fields': [
{'name': 'state', 'type': 'STRING'},
{'name': 'city', 'type': 'STRING'}
] },
{ 'name': 'amount', 'type': 'INTEGER'},
{ 'name': 'currency', 'type': 'STRING'}
]",
"function(row, emit) { // function
for (var i = 0; i < row.locations.length; i++) {
var c = [];
x = row.locations[i].split(',');
t = {state:x[0], city:x[1]}
c.push(t);
emit({amount: row.amount, currency: row.currency, location: c});
};
}"
)
Output here is:
[
{
"amount": "40",
"currency": "coins",
"location_state": "romania",
"location_city": "transylvania"
},
{
"amount": "40",
"currency": "coins",
"location_state": "florida",
"location_city": "miami"
},
{
"amount": "40",
"currency": "coins",
"location_state": "california",
"location_city": "la"
}
]

Answer 2

You need to use the dot notation to reflect the output as a RECORD example query:
select
'florida' as country.state,
'SFO' as country.city;
In this example country is the record and state|city are fields in the record.