COUNT() GROUP BY ...
All functions > GROUP BY > COUNT() GROUP BY ...
Returns the number of values in the group.
Syntax
Diagram(
Sequence(
Terminal("COUNT"),
Terminal("("),
NonTerminal("expr"),
Terminal(")"),
Choice(0, Skip(),
Sequence(
Terminal("FILTER"),
Terminal("("),
Terminal("WHERE"),
NonTerminal("condition"),
Terminal(")")
)
),
Choice(0, Skip(),
Sequence(
Terminal("GROUP BY"),
OneOrMore(NonTerminal("feature"), Terminal(","))
)
)
)
)| Parameter | Type | Required | Description |
|---|---|---|---|
expr | T | Yes | The expression to count |
condition | BOOLEAN | No | The condition to filter the values before aggregation |
feature | FEATURE | No | The features to group by (many features are supported) |
Notes
- Counts non-NULL values in the group
- NULL values are excluded from the count
- Returns 0 for empty groups
- Can be used with WHERE clause to filter before counting
- Can be used with GROUP BY clause for grouped counts
- Use COUNT(*) to count all rows including NULLs
Examples
FeatureQL
SELECT
f1 := ZIP(ARRAY[1, 2, 3, 4, 5] AS value).TRANSFORM(SELECT COUNT(value)).UNWRAP_ONE(), -- Count of values
f2 := ZIP(ARRAY[1, NULL::BIGINT, 3, NULL::BIGINT, 5] AS value).TRANSFORM(SELECT COUNT(value)).UNWRAP_ONE() -- Count of values excluding NULLs
;Result
| f1 BIGINT | f2 BIGINT |
|---|---|
| 5 | 3 |