ARRAY_LOOKUP(...)
All functions > ARRAY > ARRAY_LOOKUP(...)
Returns the value corresponding to a lookup key using parallel key-value arrays.
Signatures
Returns: The value at the same position as the key
ARRAY_LOOKUP(lookup_key: T, keys: ARRAY<T>, values: ARRAY<U>) → Usql
| Parameter | Type | Required | Description |
|---|---|---|---|
lookup_key | T | Yes | The key to search for |
keys | ARRAY<T> | Yes | Array of keys |
values | ARRAY<U> | Yes | Array of values (parallel to keys) |
Notes
- Uses two parallel arrays: one for keys, one for values
- Returns the value at the same index where the key is found
- Returns NULL if key is not found
- Only returns the first match if key appears multiple times
- Arrays must be same length
See also
Examples
FeatureQL
SELECT
f1 := ARRAY_LOOKUP('b', ARRAY('a', 'b', 'c'), ARRAY(10, 20, 30)), -- Find value by key in parallel arrays
f2 := ARRAY_LOOKUP('x', ARRAY('a', 'b', 'c'), ARRAY(10, 20, 30)), -- Returns NULL when key is not found
f3 := ARRAY_LOOKUP(2, ARRAY(1, 2, 3), ARRAY('first', 'second', 'third')), -- Numeric keys with string values
f4 := ARRAY_LOOKUP('a', ARRAY('a', 'a', 'b'), ARRAY(1, 2, 3)) -- Returns first match when key appears multiple times
;Result
| f1 BIGINT | f2 BIGINT | f3 VARCHAR | f4 BIGINT |
|---|---|---|---|
| 20 | NULL | second | 1 |
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