How do I change an integer to a date in SQL?

Converting an integer to a date in SQL depends on the specific database system you are using, as different systems have different functions and conventions for date handling. The integer typically represents the number of days since a specific base date (epoch).

Here's how you can do it in some common SQL databases:

1. MySQL:

- MySQL uses the DATE_ADD() function along with the INTERVAL keyword. The base date is typically '0000-00-00'.

- Example:

SELECT DATE_ADD('0000-00-00', INTERVAL your_integer_column DAY) AS converted_date FROM your_table;

- Replace your_integer_column with the name of your integer column and your_table with your table name.

2. PostgreSQL:

- PostgreSQL uses the DATE type and the INTERVAL keyword. The base date is typically '1970-01-01'.

- Example:

SELECT DATE '1970-01-01' + your_integer_column INTERVAL '1 day' AS converted_date FROM your_table;

- Replace your_integer_column with the name of your integer column and your_table with your table name.

3. SQL Server:

- SQL Server uses the DATEADD() function. The base date is typically '1900-01-01'.

- Example:

SELECT DATEADD(day, your_integer_column, '1900-01-01') AS converted_date FROM your_table;

- Replace your_integer_column with the name of your integer column and your_table with your table name.

4. Oracle:

- Oracle uses the DATE type and adds the integer directly to the base date. The base date is typically '1970-01-01'.

- Example:

SELECT DATE '1970-01-01' + your_integer_column AS converted_date FROM your_table;

- Replace your_integer_column with the name of your integer column and your_table with your table name.

Important Considerations:

- Base Date: Ensure you know the correct base date for your integer representation. This is crucial for accurate conversion.

- Time Zones: If your dates involve time zones, you may need to adjust the conversion accordingly.

- Error Handling: Consider adding error handling to deal with invalid integer values that might result in incorrect dates.

By using the appropriate functions and base dates for your specific database system, you can effectively convert an integer to a date in SQL.

Learn more about this