How do you connect to different data sources in Power BI, which connection type do you select, and what things must you check before importing via an SQL script?
Asked in the Technical Round stage. Initial technical questions focused on data ingestion and SQL preparation.
Write a PostgreSQL query that audits source transactions before they are imported into Power BI. Identify missing customer relationships, null required fields, non-positive amounts, and duplicate source references.
transaction_id, customer_id, transaction_date, amount, import_status, and validation_issue.Ready only when all checks pass; otherwise mark them Review.transaction_id ascending.| Column | Type | Description |
|---|---|---|
| transaction_idPK | INT | Unique source transaction identifier |
| customer_id | INT | Customer associated with the transaction |
| transaction_date | DATE | Date the transaction occurred |
| amount | NUMERIC(12,2) | Transaction amount |
| source_reference | VARCHAR(30) | Reference supplied by the source system |
| Column | Type | Description |
|---|---|---|
| customer_idPK | INT | Unique customer identifier |
| customer_name | VARCHAR(100) | Customer display name |
| customer_status | VARCHAR(20) | Current customer status |