How can I subtract an interval from a DATE in Databricks SQL, ensuring a well-formed resulting date and handling overflow with an error?
To subtract an interval from a DATE in Databricks SQL, ensuring a well-formed resulting date and handling overflow with an error, you can use the '-' operator as shown in the examples below:

```sql
SELECT DATE'2021-03-20' - INTERVAL '2' MONTH
```

This query subtracts an interval of 2 months from the DATE '2021-03-20', resulting in a well-formed date of '2021-01-20'.

To handle overflow with an error, you can use the 'try_subtract' function, which returns NULL instead of raising an error. However, if you want to raise an error, you can use the '-' operator directly, as shown in the following example:

```sql
SELECT DATE'2021-03-31' - INTERVAL '1' MONTH
```

This query subtracts an interval of 1 month from the DATE '2021-03-31', resulting in an overflow error, as the resulting date would be '2021-03-01', which is not a well-formed date.

To avoid this error, you can use the 'try_subtract' function instead:

```sql
SELECT try_subtract(DATE'2021-03-31', INTERVAL '1' MONTH)
```

This query returns NULL instead of raising an error.