# COLLECT\$1LIST function
<a name="COLLECT_LIST"></a>

The COLLECT\$1LIST function collects and returns a list of non-unique elements. 

This type of function is useful when you want to collect multiple values from a set of rows into a single array or list data structure.

**Note**  
The function is non-deterministic because the order of the collected results depends on the order of the rows, which may be non-deterministic after a shuffle operation is performed.

## Syntax
<a name="COLLECT_LIST-syntax"></a>

```
collect_list(expr)
```

## Arguments
<a name="COLLECT_LIST-arguments"></a>

 *expr*   
An expression of any type.

## Returns
<a name="COLLECT_LIST-returns"></a>

Returns an ARRAY of the argument type. The order of elements in the array is non-deterministic. 

NULL values are excluded.

If DISTINCT is specified, the function collects only unique values and is a synonym for `collect_set `aggregate function.

## Example
<a name="COLLECT_LIST-example"></a>

The following query collects all the values from the col column into a list. The `VALUES` clause is used to create an inline table with three rows, where each row has a single column col with the values 1, 2, and 1 respectively. The `collect_list() `function is then used to aggregate all the values from the col column into a single array. The output of this SQL statement would be the array `[1,2,1]`, which contains all the values from the col column in the order they appeared in the input data.

```
SELECT collect_list(col) FROM VALUES (1), (2), (1) AS tab(col);
 [1,2,1]
```