versioned_docs/version-3.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 (usually column names). |

## 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 varchar(20)) distributed by hash(c1) buckets 1 properties ("replication_num"="1");
insert into test_doris_array_agg values (1,'a'),(1,'b'),(2,'c'),(2,null),(3,null);
```

```sql
select * from test_doris_array_agg;
```

```text
+------+------+

| c1   | c2   |

+------+------+

|    1 | a    |

|    1 | b    |

|    2 | c    |

|    2 | NULL |

|    3 | NULL |

+------+------+
```

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

```text
+------+-----------------+

| c1   | array_agg(`c2`) |

+------+-----------------+

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

|    2 | [NULL,"c"]      |

|    3 | [NULL]          |

+------+-----------------+
```