UNWRAP_ONE

All functions > ARRAY OF ROWS > UNWRAP_ONE

Returns the value of the first field of the first element in an array of single-field rows.

Signatures

Returns: Value of the first field from the first element

UNWRAP_ONE(array: ARRAY<ROW<T>>) → T

Notes

• Extracts the first field value from the first row in an array
• Only works with arrays of rows that have exactly one field
• Throws error if row has multiple fields
• Useful for unwrapping aggregation results

Examples

SELECT
    f1 := UNWRAP_ONE(ARRAY(ROW(1), ROW(2), ROW(3))),  -- Extract first field from first row
    f2 := UNWRAP_ONE(ARRAY(ROW('a'), ROW('b'))),  -- Extract string from first row
    f3 := UNWRAP_ONE(ARRAY(ROW(ARRAY(1, 2, 3)))),  -- Extract array from first row
    f4 := ARRAY(ROW('a')).UNWRAP_ONE()  -- Method syntax for unwrapping
;