versioned_docs/version-4.x/sql-manual/sql-functions/aggregate-functions/array-agg.md

---
{
    "title": "ARRAY_AGG",
    "language": "en",
    "description": "Concatenates the values (including null values) in a column into an array, which can be used for pivoting rows into columns."
}
---

## Description

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

## Syntax

```sql
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

```sql
-- 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);
```

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

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

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

```text
+---------------+
| array_agg(c2) |
+---------------+
| []            |
+---------------+
```
|    1 | ["a","b"]       |