Categories:
Semi-structured Data Functions (Array/Object)

ARRAY_TO_STRING

Returns an input array converted to a string by casting all values to strings (using TO_VARCHAR) and concatenating them (using the string from the second argument to separate the elements).

Syntax

ARRAY_TO_STRING( <array> , <separator_string> )

Arguments

array
The array of elements to convert to a string.
separator_string
The string to put between each element, typically a space, comma, or other human-readable separator.

Returns

The data type of the returned value is VARCHAR.

Usage Notes

  • A NULL argument returns NULL as a result.
  • To include a blank space between values, the separator_string must include both the separator character and the blank space (e.g. ', '). Seem the example(s) below.

Examples

SELECT column1,
    ARRAY_TO_STRING(PARSE_JSON(column1), '') AS no_separation,
    ARRAY_TO_STRING(PARSE_JSON(column1), ', ') AS comma_separated
  FROM VALUES
    (NULL),
    ('[]'),
    ('[1]'),
    ('[1, 2]'),
    ('[true, 1, -1.2e-3, "Abc", ["x","y"], {"a":1}]'),
    ('[, 1]'),
    ('[1, ]'),
    ('[1, , ,2]');
+-----------------------------------------------+---------------------------------+-------------------------------------------+
| COLUMN1                                       | NO_SEPARATION                   | COMMA_SEPARATED                           |
|-----------------------------------------------+---------------------------------+-------------------------------------------|
| NULL                                          | NULL                            | NULL                                      |
| []                                            |                                 |                                           |
| [1]                                           | 1                               | 1                                         |
| [1, 2]                                        | 12                              | 1, 2                                      |
| [true, 1, -1.2e-3, "Abc", ["x","y"], {"a":1}] | true1-0.0012Abc["x","y"]{"a":1} | true, 1, -0.0012, Abc, ["x","y"], {"a":1} |
| [, 1]                                         | 1                               | , 1                                       |
| [1, ]                                         | 1                               | 1,                                        |
| [1, , ,2]                                     | 12                              | 1, , , 2                                  |
+-----------------------------------------------+---------------------------------+-------------------------------------------+