Tell me about a time you used SQL and Tableau to analyze a messy or unclear question, including the assumptions you made and how you validated them.
Use the supplied tables to produce a representative SQL validation output that identifies record volume, distinct entities, missing values, and repeated entities by source.
source_name, rows_loaded, distinct_entities, null_value_rows, duplicate_entity_rowssource_name alphabetically| Column | Type | Description |
|---|---|---|
| source_idPK | INT | Unique identifier for a data source |
| source_name | VARCHAR(100) | Display name of the data source |
| expected_grain | VARCHAR(100) | Expected level of detail for source records |
| Column | Type | Description |
|---|---|---|
| record_idPK | INT | Unique record identifier |
| source_id | INT | Identifier of the source that supplied the record |
| entity_id | INT | Entity associated with the record |
| observed_value | DECIMAL(10,2) | Measured value used in analysis |
| captured_at | DATE | Date the record was captured |