ELEMENTS_AT_KEY()

All functions > ARRAY OF ROWS > ELEMENTS_AT_KEY()

Returns multiple elements at the given key from the given index, array or array of rows.

Signatures

Returns: Multiple elements at the positions indicated by index[key]

ELEMENTS_AT_KEY(index: INDEX, key: T, base: ARRAY<ROW<T>>) → ARRAY<ROW<T>>

Notes

• Uses index to map key to multiple array positions
• Looks up key in index to find array of positions
• Returns elements at those positions from base array
• Returns empty array if key not found in index
• Useful for one-to-many lookups with multi-valued indexes

Examples

SELECT
    f1 := ELEMENTS_AT_KEY(INDEX_MULTI(ARRAY[ROW(1 AS k, 'a' AS v), ROW(1 AS k, 'b' AS v)] BY k), 1) -- All rows for a key (INDEX_MULTI index)
;