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SQL Problem Solving Walkthrough
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SQL Problem Solving Walkthrough

HardSQL · PostgreSQL

Problem

Given a dataset, how would you analyze it or solve the problem?

Use the provided relational dataset to produce a concise monthly analysis for January through March 2025. Include qualifying accepted records with matching event details, while retaining entities and months with no qualifying activity.

Output

  1. One row per entity and calendar month.
  2. Columns: entity_name, segment, month, accepted_records, total_amount, prior_month_total, pct_change, and segment_rank.
  3. Include all entities for all three months, calculate percentage change only when the prior total is positive, rank entities within each segment and month by total amount descending, and order by segment, month, segment_rank, and entity_name.

Schema

dataset_entities
ColumnTypeDescription
entity_idPKINTUnique entity identifier
entity_nameVARCHAR(100)Entity display name
segmentVARCHAR(50)Entity segment
dataset_records
ColumnTypeDescription
record_idPKINTUnique record identifier
entity_idINTReferenced entity
event_idINTReferenced event, when available
record_dateDATERecord date
amountNUMERIC(12,2)Record amount
statusVARCHAR(20)Record processing status
dataset_events
ColumnTypeDescription
event_idPKINTUnique event identifier
event_typeVARCHAR(30)Event classification
sourceVARCHAR(50)Event source system
Tablesdataset_entitiesdataset_recordsdataset_events
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