ARRAY_CONCAT
Alias: ARRAY_CAT
Combines one or more arrays that are passed as arguments.
Syntax
ARRAY_CONCAT(<array> [, ...n])
—OR—
<expression> || <expression>
Parameters
| Parameter | Description | Supported input types |
|---|---|---|
<array> [, ...n] | The arrays to be combined. If only one array is given, an identical array is returned. | ARRAY |
|| operator
| Parameter | Description | Supported input types |
|---|---|---|
<expression> | The expressions to be concatenated. | TEXT / ARRAY, but at least one ARRAY |
To enable array concatenation, one parameter to the || operator must be of type ARRAY, while the other parameter can be a string whose value can be converted to the underlying type of the array parameter, or it can be an array of the same type.
If one parameter to the || operator is NULL, the result will be the non-null parameter; if both parameters are NULL, the result will be NULL.
The concatenation operator || can also be used for string concatenation.
Return Type
ARRAY of the same type as the input arrays
Example
In the following example, two arrays are combined to show all of the levels in a particular game:
SELECT
ARRAY_CONCAT([ 1, 2, 3, 4 ], [ 5, 6, 7, 8, 9, 10 ]) AS levels;
Returns: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
The following example concatenates two integer arrays:
SELECT ARRAY[1,2] || ARRAY[3];
Returns: [1, 2, 3]
The following example concatenates a string, whose value can be converted to integer, with an integer array:
SELECT '{2}' || ARRAY[1];
Returns: [2, 1]