ARRAY_AGG

Description

Concatenates the values (including null values) in a column into an array, which can be used for pivoting rows into columns.

Syntax

ARRAY_AGG(<col>)

Parameters

Parameter	Description
<col>	An expression that determines the values to be placed into the array. Supported types: Bool, TinyInt, SmallInt, Integer, BigInt, LargeInt, Float, Double, Decimal, Date, Datetime, IPV4, IPV6, String, Array, Map, Struct.

Return Value

Returns a value of ARRAY type.Special cases:

• The order of elements in the array is not guaranteed.
• Returns the array generated by the conversion. The element type in the array is consistent with the type of col.

Example

-- setup
CREATE TABLE test_doris_array_agg (
	c1 INT,
	c2 INT
) DISTRIBUTED BY HASH(c1) BUCKETS 1
PROPERTIES ("replication_num" = "1");
INSERT INTO test_doris_array_agg VALUES (1, 10), (1, 20), (1, 30), (2, 100), (2, 200), (3, NULL);

select c1, array_agg(c2) from test_doris_array_agg group by c1;

+------+---------------+
| c1   | array_agg(c2) |
+------+---------------+
|    1 | [10, 20, 30]  |
|    2 | [100, 200]    |
|    3 | [null]        |
+------+---------------+

select array_agg(c2) from test_doris_array_agg where c1 is null;

+---------------+
| array_agg(c2) |
+---------------+
| []            |
+---------------+

| 1 | ["a","b"] |