Special Functions¶
Expansion Functions¶
unnest¶
Expands an array or map into rows.
Arguments¶
array: Array expression to unnest. Can be a constant, column, or function, and any combination of array operators.
Examples¶
> select unnest(make_array(1, 2, 3, 4, 5)) as unnested;
+----------+
| unnested |
+----------+
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
+----------+
> select unnest(range(0, 10)) as unnested_range;
+----------------+
| unnested_range |
+----------------+
| 0 |
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
| 6 |
| 7 |
| 8 |
| 9 |
+----------------+
unnest (struct)¶
Expand a struct fields into individual columns.
Arguments¶
struct: Object expression to unnest. Can be a constant, column, or function, and any combination of object operators.
Examples¶
> create table foo as values ({a: 5, b: 'a string'}), ({a:6, b: 'another string'});
> create view foov as select column1 as struct_column from foo;
> select * from foov;
+---------------------------+
| struct_column |
+---------------------------+
| {a: 5, b: a string} |
| {a: 6, b: another string} |
+---------------------------+
> select unnest(struct_column) from foov;
+------------------------------------------+------------------------------------------+
| unnest_placeholder(foov.struct_column).a | unnest_placeholder(foov.struct_column).b |
+------------------------------------------+------------------------------------------+
| 5 | a string |
| 6 | another string |
+------------------------------------------+------------------------------------------+