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task GROUP BY · medium

Grid review 1: regional demand on a peak day

For the UTC day 2024-06-20 (hours ending after 00:00 and up to 24:00), return region_code, authorities (balancing authorities reporting) and demand_mwh (sum of known demand_mw).

what to return

Columns
region_codeauthoritiesdemand_mwh in this order
Rows
12 rows · any order
Watch for
Every stage starts from the original tables.
Use hour_ending_utc for ordering and periods; MW over one hour equals MWh.
NULL measurements are unknown: exclude them from averages and ratios, never treat them as zero.
Skill
Establish regional totals before investigating reliability. Refresher: Connect tables with JOIN →

expected result

Your query should return exactly these columns and values. Run it and compare.

expected result12 rows · any order
region_codeauthoritiesdemand_mwh
CAL1622208
CAR1342017
CENT1883693

first 3 of 12 rows

data you can query

Energy dataset: the first 6 rows of each table. Under each column name: the kind of value it holds, and which table it links to. Your queries run on all rows.

hourly_demand9 columns · 52,405 rows
ba_codetext · links to balancing_authoritieshour_ending_utcdate & time · unique idhour_ending_localdate & timedemand_mwnumberforecast_mwnumberlocal_datedate · links to calendarhour_numbernumberadjusted_demand_mwnumberdemand_imputednumber
BPAT2024-01-01 09:002024-01-01 01:00630263092024-01-01163020
BPAT2024-01-01 10:002024-01-01 02:00623062362024-01-01262300
BPAT2024-01-01 11:002024-01-01 03:00617962652024-01-01361790
BPAT2024-01-01 12:002024-01-01 04:00619762772024-01-01461970
BPAT2024-01-01 13:002024-01-01 05:00637863942024-01-01563780
BPAT2024-01-01 14:002024-01-01 06:00660766252024-01-01666070
ba_codetext · links to balancing_authorities
BPAT
hour_ending_utcdate & time · unique id
2024-01-01 09:00
hour_ending_localdate & time
2024-01-01 01:00
demand_mwnumber
6302
forecast_mwnumber
6309
local_datedate · links to calendar
2024-01-01
hour_numbernumber
1
adjusted_demand_mwnumber
6302
demand_imputednumber
0
ba_codetext · links to balancing_authorities
BPAT
hour_ending_utcdate & time · unique id
2024-01-01 10:00
hour_ending_localdate & time
2024-01-01 02:00
demand_mwnumber
6230
forecast_mwnumber
6236
local_datedate · links to calendar
2024-01-01
hour_numbernumber
2
adjusted_demand_mwnumber
6230
demand_imputednumber
0
ba_codetext · links to balancing_authorities
BPAT
hour_ending_utcdate & time · unique id
2024-01-01 11:00
hour_ending_localdate & time
2024-01-01 03:00
demand_mwnumber
6179
forecast_mwnumber
6265
local_datedate · links to calendar
2024-01-01
hour_numbernumber
3
adjusted_demand_mwnumber
6179
demand_imputednumber
0
ba_codetext · links to balancing_authorities
BPAT
hour_ending_utcdate & time · unique id
2024-01-01 12:00
hour_ending_localdate & time
2024-01-01 04:00
demand_mwnumber
6197
forecast_mwnumber
6277
local_datedate · links to calendar
2024-01-01
hour_numbernumber
4
adjusted_demand_mwnumber
6197
demand_imputednumber
0
ba_codetext · links to balancing_authorities
BPAT
hour_ending_utcdate & time · unique id
2024-01-01 13:00
hour_ending_localdate & time
2024-01-01 05:00
demand_mwnumber
6378
forecast_mwnumber
6394
local_datedate · links to calendar
2024-01-01
hour_numbernumber
5
adjusted_demand_mwnumber
6378
demand_imputednumber
0
ba_codetext · links to balancing_authorities
BPAT
hour_ending_utcdate & time · unique id
2024-01-01 14:00
hour_ending_localdate & time
2024-01-01 06:00
demand_mwnumber
6607
forecast_mwnumber
6625
local_datedate · links to calendar
2024-01-01
hour_numbernumber
6
adjusted_demand_mwnumber
6607
demand_imputednumber
0

first 6 of 52,405 rows · your queries use all of them

balancing_authorities6 columns · 62 rows
ba_codetext · unique idba_nametexttime_zonetextregion_codetext · links to regionsgeneration_onlynumberhourly_detailnumber
AECIAssociated Electric Cooperative, Inc.CentralMIDW00
AVAAvista CorporationPacificNW00
AVRNAvangrid Renewables, LLCPacificNW10
AZPSArizona Public Service CompanyArizonaSW00
BANCBalancing Authority of Northern CaliforniaPacificCAL00
BCHABritish Columbia Hydro and Power AuthorityCAN00
ba_codetext · unique id
AECI
ba_nametext
Associated Electric Cooperative, Inc.
time_zonetext
Central
region_codetext · links to regions
MIDW
generation_onlynumber
0
hourly_detailnumber
0
ba_codetext · unique id
AVA
ba_nametext
Avista Corporation
time_zonetext
Pacific
region_codetext · links to regions
NW
generation_onlynumber
0
hourly_detailnumber
0
ba_codetext · unique id
AVRN
ba_nametext
Avangrid Renewables, LLC
time_zonetext
Pacific
region_codetext · links to regions
NW
generation_onlynumber
1
hourly_detailnumber
0
ba_codetext · unique id
AZPS
ba_nametext
Arizona Public Service Company
time_zonetext
Arizona
region_codetext · links to regions
SW
generation_onlynumber
0
hourly_detailnumber
0
ba_codetext · unique id
BANC
ba_nametext
Balancing Authority of Northern California
time_zonetext
Pacific
region_codetext · links to regions
CAL
generation_onlynumber
0
hourly_detailnumber
0
ba_codetext · unique id
BCHA
ba_nametext
British Columbia Hydro and Power Authority
time_zonetext
region_codetext · links to regions
CAN
generation_onlynumber
0
hourly_detailnumber
0

first 6 of 62 rows · your queries use all of them

solution.sql
 

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Grid review 1: regional demand on a peak day — SQL practice · Runtime