flatten function

Applies to: check marked yes Databricks SQL check marked yes Databricks Runtime

Transforms an array of arrays into a single array.

Syntax 

flatten(expr)

Arguments

  • expr: An ARRAY of ARRAY expression.

Returns

The result matches the type of the nested arrays within expr.

Examples 

> SELECT flatten(array(array(1, 2), array(3, 4)));
 [1,2,3,4]