Converting Strings to Dates in Databricks
Converting strings to dates in Databricks can be achieved using the to_date function. This function allows you to convert a string representing a date into a standardized date format, making it easier to perform date-related operations.
Syntax and Usage
The syntax for the to_date function is as follows:
to_date(expr [, fmt])
Here, expr is the string expression representing a date, and fmt is an optional format string that specifies how the input string should be interpreted.
Examples
Without specifying a format, the function assumes the input string is in the ‘yyyy-MM-dd’ format:
SELECT to_date('2021-10-07');
This will return the date ‘2021-10-07’.
To convert a string in a different format, you can specify the format:
SELECT to_date('10-07-2021', 'dd-MM-yyyy');
This will also return the date ‘2021-07-10’.
Common Format Specifiers
| Specifier | Description |
|---|---|
| yyyy | Four-digit year |
| MM | Two-digit month (01 to 12) |
| dd | Two-digit day of the month (01 to 31) |
| MMM | Abbreviated month name (e.g., Jan) |
Frequently Asked Questions
- Q: How do I convert a string to a timestamp in Databricks?
A: You can use the to_timestamp function with the appropriate format specifier. For example,
SELECT to_timestamp('10-07-2021 13:25:35', 'dd-MM-yyyy HH:mm:ss'); - Q: What happens if the input string does not match the specified format?
A: If the format is malformed or does not result in a well-formed date, the function will raise an error unless spark.sql.ansi.enabled is set to false, in which case it returns NULL.
- Q: Can I use the to_date function without specifying a format?
A: Yes, if you do not specify a format, the function assumes the input string is in the ‘yyyy-MM-dd’ format.
- Q: How do I convert an integer representing seconds since the Unix epoch to a date?
A: You can use the to_date(timestamp_seconds(int)) function. For example,
SELECT to_date(timestamp_seconds(1350219000));
- Q: Can I convert a decimal representing seconds since the Unix epoch to a date?
A: Yes, you can use the to_date(timestamp_seconds(decimal)) function.
- Q: How do I format a date in Databricks to display it in a specific format?
A: You can use the date_format function to transform a date into a desired format. For example,
SELECT date_format(current_date, 'yyyy-MM-dd');
- Q: Can I use the to_date function with time zone information?
A: While the to_date function itself does not directly handle time zones, you can consider using timestamps with time zone information for more complex scenarios.
Bottom Line
Converting strings to dates in Databricks is straightforward using the to_date function. By specifying the correct format for your input strings, you can efficiently handle date-related data and perform various date operations.