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| product | date_from | date_to |
|---|---|---|
| 1 | 2020-01-01 | 2020-01-03 |
| 1 | 2020-01-05 | 2020-01-10 |
SELECT 2
| product | date_from | date_to |
|---|---|---|
| 1 | 2020-01-01 | 2020-01-03 |
| 1 | 2020-01-05 | 2020-01-10 |
SELECT 2