Generator functions - Amazon OpenSearch Service

Generator functions

Note

To see which AWS data source integrations support these SQL functions, see Supported OpenSearch SQL commands and functions.

Function Description
explode(expr) Separates the elements of array `expr` into multiple rows, or the elements of map `expr` into multiple rows and columns. Unless specified otherwise, uses the default column name `col` for elements of the array or `key` and `value` for the elements of the map.
explode_outer(expr) Separates the elements of array `expr` into multiple rows, or the elements of map `expr` into multiple rows and columns. Unless specified otherwise, uses the default column name `col` for elements of the array or `key` and `value` for the elements of the map.
inline(expr) Explodes an array of structs into a table. Uses column names col1, col2, etc. by default unless specified otherwise.
inline_outer(expr) Explodes an array of structs into a table. Uses column names col1, col2, etc. by default unless specified otherwise.
posexplode(expr) Separates the elements of array `expr` into multiple rows with positions, or the elements of map `expr` into multiple rows and columns with positions. Unless specified otherwise, uses the column name `pos` for position, `col` for elements of the array or `key` and `value` for elements of the map.
posexplode_outer(expr) Separates the elements of array `expr` into multiple rows with positions, or the elements of map `expr` into multiple rows and columns with positions. Unless specified otherwise, uses the column name `pos` for position, `col` for elements of the array or `key` and `value` for elements of the map.
stack(n, expr1, ..., exprk) Separates `expr1`, ..., `exprk` into `n` rows. Uses column names col0, col1, etc. by default unless specified otherwise.

Examples

-- explode
SELECT explode(array(10, 20));
+---+
|col|
+---+
| 10|
| 20|
+---+

SELECT explode(collection => array(10, 20));
+---+
|col|
+---+
| 10|
| 20|
+---+

SELECT * FROM explode(collection => array(10, 20));
+---+
|col|
+---+
| 10|
| 20|
+---+

-- explode_outer
SELECT explode_outer(array(10, 20));
+---+
|col|
+---+
| 10|
| 20|
+---+

SELECT explode_outer(collection => array(10, 20));
+---+
|col|
+---+
| 10|
| 20|
+---+

SELECT * FROM explode_outer(collection => array(10, 20));
+---+
|col|
+---+
| 10|
| 20|
+---+

-- inline
SELECT inline(array(struct(1, 'a'), struct(2, 'b')));
+----+----+
|col1|col2|
+----+----+
|   1|   a|
|   2|   b|
+----+----+

-- inline_outer
SELECT inline_outer(array(struct(1, 'a'), struct(2, 'b')));
+----+----+
|col1|col2|
+----+----+
|   1|   a|
|   2|   b|
+----+----+

-- posexplode
SELECT posexplode(array(10,20));
+---+---+
|pos|col|
+---+---+
|  0| 10|
|  1| 20|
+---+---+

SELECT * FROM posexplode(array(10,20));
+---+---+
|pos|col|
+---+---+
|  0| 10|
|  1| 20|
+---+---+

-- posexplode_outer
SELECT posexplode_outer(array(10,20));
+---+---+
|pos|col|
+---+---+
|  0| 10|
|  1| 20|
+---+---+

SELECT * FROM posexplode_outer(array(10,20));
+---+---+
|pos|col|
+---+---+
|  0| 10|
|  1| 20|
+---+---+

-- stack
SELECT stack(2, 1, 2, 3);
+----+----+
|col0|col1|
+----+----+
|   1|   2|
|   3|NULL|
+----+----+