to_csv function
Applies to: 
Databricks SQL Databricks Runtime
Returns a CSV string with the specified struct value.
Syntax
to_csv(expr [, options] )
Arguments
expr: A STRUCT expression.options: An optional MAP literal expression with keys and values being STRING.
Returns
A STRING.
See from_csv function for details on possible options.
Examples
SQL
> SELECT to_csv(named_struct('a', 1, 'b', 2));
1,2
> SELECT to_csv(named_struct('time', to_timestamp('2015-08-26', 'yyyy-MM-dd')), map('timestampFormat', 'dd/MM/yyyy'));
26/08/2015