# Special Functions ## Expansion Functions - [unnest](#unnest) - [unnest(struct)](#unnest-struct) ### `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 ```sql > select unnest(make_array(1, 2, 3, 4, 5)) as unnested; +----------+ | unnested | +----------+ | 1 | | 2 | | 3 | | 4 | | 5 | +----------+ ``` ```sql > 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. Each field of the struct can be accessed via `".."`. #### Arguments - **struct**: Object expression to unnest. Can be a constant, column, or function, and any combination of object operators. #### Examples ```sql > 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; +--------------------------------------------+--------------------------------------------+ | foov.struct_column.a | foov.struct_column.b | +--------------------------------------------+--------------------------------------------+ | 5 | a string | | 6 | another string | +--------------------------------------------+--------------------------------------------+ ```