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| a1 | a2 | (No column name) |
|---|---|---|
| a | 1 | null |
| a | 3 | 1 |
| a | 5 | 3 |
| a | 9 | 5 |
| b | 1 | null |
| b | 3 | 1 |
| b | 4 | 3 |
| c | 3 | null |
| c | 4 | 3 |
| c | 5 | 4 |
| a1 | a2 | new_col_name |
|---|---|---|
| a | 1 | null |
| a | 3 | 1 |
| a | 5 | 3 |
| a | 9 | 5 |
| b | 1 | null |
| b | 3 | 1 |
| b | 4 | 3 |
| c | 3 | null |
| c | 4 | 3 |
| c | 5 | 4 |
| a1 | a2 | new_column |
|---|---|---|
| a | 1 | null |
| a | 3 | 1 |
| a | 5 | 3 |
| a | 9 | 5 |
| b | 1 | null |
| b | 3 | 1 |
| b | 4 | 3 |
| c | 3 | null |
| c | 4 | 3 |
| c | 5 | 4 |