Support for PG array_to_string() - concat elements of an array to string / text with a delimiter

Use case: Support for PG array_to_string() function in CrateDB.

This now can be done as workaround with an UDF for TEXT:

CREATE OR REPLACE function array_to_string(array(TEXT),TEXT)
RETURNS TEXT
LANGUAGE JAVASCRIPT
AS 'function array_to_string(arr, delimiter) { return Array.prototype.join.call(arr, delimiter);}';

SELECT array_to_string(['a','b','c'],',');

Feature description:

There is an array_to_string() function that concats elements with a delimiter (optionally replace NULL values

From PostgreSQL

array_to_string ( array anyarray, delimiter text [, null_string text ] ) → text Converts each array element to its text representation, and concatenates those separated by the delimiter string. If null_string is given and is not NULL, then NULL array entries are represented by that string; otherwise, they are omitted. array_to_string(ARRAY[1, 2, 3, NULL, 5], ‘,’, '') → 1,2,3,,5

[proddata]

@BaurzhanSakhariev

array_to_string() would be a scalar function, similar to #10662 i.e. basically an extensions to the other aggregations in there

[proddata]

Isn’t this string_agg ?

array_to_string would be a scalar function It really would be the counterpart to string_to_array()

One would have to unnest the array to use string_agg() first, which might not work with different length arrays in a recordset