# COUNT

> COUNT aggregate function in StackQL: the number of rows in a resource, or the non-NULL values of a column within a grouping.

Source: https://stackql.io/language-spec/functions/aggregate/count

Returns the total number of records in a resource or a count of the non `NULL` instances of a column in a grouping.  

See also:  
[[` SELECT `]](/language-spec/select)

* * * 

## Syntax

```sql
SELECT COUNT( * | columnExpression ) FROM <multipartIdentifier>
[ GROUP BY groupByColumn ];
```

## Arguments

__*columnExpression*__  or __*__  
A column or expression.  If __*__ is specified then all records in the resource or grouping are counted.  

> At least one value from the *columnExpression* must be non `NULL` otherwise `NULL` is returned.

__*groupByColumn*__  
A column or columns used to perform summary or aggregate operations against.  The `GROUP BY` clause returns one row for each column grouping.

## Return Value(s)

Returns an integer representing the count.

* * *

## Examples

### Return the average of a column expression over an entire resource

```sql
SELECT count(*) as num_instances
FROM google.compute.instances 
WHERE project = 'stackql-demo' 
AND zone = 'australia-southeast1-a';
```

### Return the average of a column expression grouped by another column expression

```sql
SELECT tags, count(*) as num_instances
FROM google.compute.instances 
WHERE project = 'stackql-demo' 
AND zone = 'australia-southeast1-a'
GROUP BY json_extract(tags, '$.instanceType');
```

### Use `COUNT` as a window function to calculate cumulative counts

```sql
-- Track cumulative issue counts over time
SELECT
    number,
    title,
    state,
    created_at,
    COUNT(*) OVER (ORDER BY created_at) as cumulative_issues,
    COUNT(*) OVER (PARTITION BY state ORDER BY created_at) as cumulative_by_state
FROM github.issues.issues
WHERE owner = 'stackql'
  AND repo = 'stackql'
ORDER BY created_at;
```

For more information, see [https://www.sqlite.org/lang_aggfunc.html#count](https://www.sqlite.org/lang_aggfunc.html#count).