Convert JSON date date to Timestamp Field - snowflake-cloud-data-platform

Question

I have source data in JSON column in snowflake and need to convert to timestamp field.
Source data:
[
{
"end_time_of_day_of_week": {
"day_of_week": "TUESDAY",
"time_of_day": {
"hours": 23,
"minutes": 59,
"nanos": null,
"seconds": 59
}
},
"start_time_of_day_of_week": {
"day_of_week": "TUESDAY",
"time_of_day": {
"hours": null,
"minutes": null,
"nanos": null,
"seconds": null
}
}
},
{
"end_time_of_day_of_week": {
"day_of_week": "WEDNESDAY",
"time_of_day": {
"hours": 23,
"minutes": 59,
"nanos": null,
"seconds": 59
}
},
"start_time_of_day_of_week": {
"day_of_week": "WEDNESDAY",
"time_of_day": {
"hours": null,
"minutes": null,
"nanos": null,
"seconds": null
}
}
},
{
"end_time_of_day_of_week": {
"day_of_week": "THURSDAY",
"time_of_day": {
"hours": 23,
"minutes": 59,
"nanos": null,
"seconds": 59
}
},
"start_time_of_day_of_week": {
"day_of_week": "THURSDAY",
"time_of_day": {
"hours": null,
"minutes": null,
"nanos": null,
"seconds": null
}
}
},
{
"end_time_of_day_of_week": {
"day_of_week": "SATURDAY",
"time_of_day": {
"hours": 23,
"minutes": 59,
"nanos": null,
"seconds": 59
}
},
"start_time_of_day_of_week": {
"day_of_week": "SATURDAY",
"time_of_day": {
"hours": null,
"minutes": null,
"nanos": null,
"seconds": null
}
}
}
]
Target output 2 column with each days time (null will be replaced by zero):
|| start_time || end_time ||
TUESDAY 00:00 TUESDAY 23:59
WEDNESDAY 00:00 WEDNESDAY 23:59
THURSDAY 00:00 THURSDAY 23:59
SATURDAY 00:00 SATURDAY 23:59
Tuesday 23:

Answer 1

So given the data is repeated, I trimmed it to two rows:
with data(json) as (
select parse_json('[
{
"end_time_of_day_of_week": {
"day_of_week": "TUESDAY", "time_of_day": { "hours": 23, "minutes": 59, "nanos": null, "seconds": 59 }
},
"start_time_of_day_of_week": {
"day_of_week": "TUESDAY", "time_of_day": { "hours": null, "minutes": null, "nanos": null, "seconds": null }
}
},
{
"end_time_of_day_of_week": {
"day_of_week": "WEDNESDAY", "time_of_day": { "hours": 23, "minutes": 58, "nanos": null, "seconds": 59 }
},
"start_time_of_day_of_week": {
"day_of_week": "WEDNESDAY", "time_of_day": { "hours": null, "minutes": null, "nanos": null, "seconds": null }
}
}
]')
)
so using FLATTEN to unroll the ARRAY, and then accessing the fields, you can use the values. I using LPAD to make things 2 characters wide, and ZEROIFNULL to handle the variant nulls.
select f.value:"start_time_of_day_of_week" as s
,f.value:"end_time_of_day_of_week" as e
,s:day_of_week as s_dow
,s:time_of_day as s_tod
,e:day_of_week as e_dow
,e:time_of_day as e_tod
,lpad(zeroifnull(s_tod:hours::int),2,0) as s_h
,lpad(zeroifnull(s_tod:minutes::int),2,0) as s_m
,zeroifnull(s_tod:seconds::int) as s_s
,zeroifnull(s_tod:nano::int) as s_n
,lpad(zeroifnull(e_tod:hours::int),2,0) as e_h
,lpad(zeroifnull(e_tod:minutes::int),2,0) as e_m
,zeroifnull(e_tod:seconds::int) as e_s
,zeroifnull(e_tod:nano::int) as e_n
,concat( s_dow, ' ', s_h, ':', s_m ) as start_time
,concat( e_dow, ' ', e_h, ':', e_m ) as end_time
from data as d
,table(flatten(input=>d.json)) f
gives:
S
E
S_DOW
S_TOD
E_DOW
E_TOD
S_H
S_M
S_S
S_N
E_H
E_M
E_S
E_N
START_TIME
END_TIME
{ "day_of_week": "TUESDAY", "time_of_day": { "hours": null, "minutes": null, "nanos": null, "seconds": null } }
{ "day_of_week": "TUESDAY", "time_of_day": { "hours": 23, "minutes": 59, "nanos": null, "seconds": 59 } }
"TUESDAY"
{ "hours": null, "minutes": null, "nanos": null, "seconds": null }
"TUESDAY"
{ "hours": 23, "minutes": 59, "nanos": null, "seconds": 59 }
00
00
0
0
23
59
59
0
TUESDAY 00:00
TUESDAY 23:59
{ "day_of_week": "WEDNESDAY", "time_of_day": { "hours": null, "minutes": null, "nanos": null, "seconds": null } }
{ "day_of_week": "WEDNESDAY", "time_of_day": { "hours": 23, "minutes": 58, "nanos": null, "seconds": 59 } }
"WEDNESDAY"
{ "hours": null, "minutes": null, "nanos": null, "seconds": null }
"WEDNESDAY"
{ "hours": 23, "minutes": 58, "nanos": null, "seconds": 59 }
00
00
0
0
23
58
59
0
WEDNESDAY 00:00
WEDNESDAY 23:58
which can be simplified to:
select
start_time
,end_time
from (
select f.value:"start_time_of_day_of_week" as s
,f.value:"end_time_of_day_of_week" as e
,lpad(zeroifnull(s:time_of_day:hours::int),2,0) as s_h
,lpad(zeroifnull(s:time_of_day:minutes::int),2,0) as s_m
,lpad(zeroifnull(e:time_of_day:hours::int),2,0) as e_h
,lpad(zeroifnull(e:time_of_day:minutes::int),2,0) as e_m
,concat( s:day_of_week, ' ', s_h, ':', s_m ) as start_time
,concat( e:day_of_week, ' ', e_h, ':', e_m ) as end_time
from data as d
,table(flatten(input=>d.json)) f
)
START_TIME
END_TIME
TUESDAY 00:00
TUESDAY 23:59
WEDNESDAY 00:00
WEDNESDAY 23:58

Answer 2

You need to use the Snowflake flatten function to convert the JSON array to rows.
Note that your desired output is not really a timestamp. It's a string (varchar). If there were enough information to construct a timestamp, the SQL could do that and output it with a format string the way you have it. However, there's not enough information to create a timestamp so this shows how to make it a varchar formatted as your target output.
create or replace table T1(v variant);
insert into T1 select parse_json($$ >>> Paste your JSON here <<< $$);
select * from T1; -- Make sure your JSON is in the table correctly.
select * from T1, table(flatten(v)); -- Start the flattening and extraction with this.
select VALUE:start_time_of_day_of_week.day_of_week::string || ' ' ||
nvl(VALUE:start_time_of_day_of_week.time_of_day.hours::string, '00') || ':' ||
nvl(VALUE:start_time_of_day_of_week.time_of_day.minutes::string, '00')
as START_TIME
,VALUE:end_time_of_day_of_week.day_of_week::string || ' ' ||
nvl(VALUE:end_time_of_day_of_week.time_of_day.hours::string, '00') || ':' ||
nvl(VALUE:end_time_of_day_of_week.time_of_day.minutes::string, '00')
as END_TIME
from T1, table(flatten(v));
Output:
START_TIME
END_TIME
TUESDAY 00:00
TUESDAY 23:59
WEDNESDAY 00:00
WEDNESDAY 23:59
THURSDAY 00:00
THURSDAY 23:59
SATURDAY 00:00
SATURDAY 23:59