DEA-C02 Data Transformation Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  DATE_TRUNC('month', order_date)

  Why it's wrong here

  DATE_TRUNC truncates a date to the specified precision, returning a DATE. For 'month', it returns the first day of the month, not a formatted string. The result would be a DATE, not a string in 'YYYY-MM' format. Additional formatting would still be needed, so this does not directly produce the required output.

• ✗

  CONCAT(YEAR(order_date), '-', MONTH(order_date))

  Why it's wrong here

  This approach uses YEAR and MONTH functions to extract numeric parts and concatenates them with a hyphen. However, MONTH returns a number without leading zero, so January would be '1' instead of '01'. The result would not match the 'YYYY-MM' format for months 1-9. It would require additional padding logic.

• ✗

  EXTRACT(YEAR_MONTH FROM order_date)

  Why it's wrong here

  EXTRACT with YEAR_MONTH is not valid Snowflake syntax. Snowflake supports EXTRACT with individual fields like YEAR, MONTH, DAY, but not a combined YEAR_MONTH. Even if it did, it would return a numeric value, not a formatted string. Therefore, this does not meet the requirement.

• ✓

  TO_CHAR(order_date, 'YYYY-MM')

  Why this is correct

  TO_CHAR converts a date or timestamp to a string using the specified format. Using 'YYYY-MM' returns the year and month in the desired format. This is the standard function for formatting dates in Snowflake and is the simplest way to achieve the required transformation.