> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/xql-command-reference-guide/readme/functions/least.md). # least Use the `least()` function to return the smallest value from a list of expressions. ## Syntax ```sql least(, [, ...]) ``` ## Parameters | Name | Type | Required | Description | | ------------- | --------------------------------- | -------- | ----------------------------------------------------------------------------------- | | `expression1` | integer, float, string, timestamp | Yes | The first value to compare. | | `expression2` | integer, float, string, timestamp | Yes | The second value to compare. | | `...` | integer, float, string, timestamp | No | Additional values to compare. Any number of additional expressions can be provided. | ## Returns **Type**: Same as input type **Description**: The `least()` function returns the smallest value among all the provided expressions. If any input is `null`, the function may skip `null` values or return `null` depending on the implementation. ## Usage notes * **Input type**: XQL doesn't support NaN or infinite values as input and these value types also can not be returned. * **Multiple Arguments**: The function accepts two or more arguments and returns the minimum value among them. * **Type Consistency**: All arguments should be of compatible types for meaningful comparison. * **Null Handling**: If all inputs are `null`, the function returns `null`. If some inputs are `null`, the function typically returns the least non-null value. * **String Comparison**: When comparing strings, the function uses lexicographic (alphabetical) ordering. * **Relationship to greatest()**: The `least()` function is the counterpart of `greatest()`, which returns the largest value. * **Common Use Cases**: This function is typically used within the `alter` stage for selecting the minimum value across multiple fields, implementing upper bounds (capping values), and data normalization. ## Examples ### Example 1: Find least among literal values **Goal**: Find the smallest value from a set of numeric literals. **XQL code**: ```sql dataset = xdr_data | limit 1 | alter min_val = least(10, 25, 5, 42, 18) | fields min_val ``` **Explanation**: The `least()` function compares all five literal values and returns `5`, the smallest among them. **Output**: | MIN\_VAL | | -------- | | 5 | ### Example 2: Find least value across multiple fields **Goal**: Find the smallest value among multiple numeric fields for each record. **XQL code**: ```sql config timeframe = 1d | dataset = sample_xql_raw | alter min_field = least(event_id, numeric_value, duration_seconds) | fields event_id, numeric_value, duration_seconds, min_field | limit 3 ``` **Explanation**: This query compares the values of `event_id`, `numeric_value`, and `duration_seconds` for each record and returns the smallest value in `min_field`. **Output**: | EVENT\_ID | NUMERIC\_VALUE | DURATION\_SECONDS | MIN\_FIELD | | --------- | -------------- | ----------------- | ---------- | | 101 | 5.0 | 1.5 | 1.5 | | 102 | 200.0 | 0.8 | 0.8 | | 103 | 50.0 | 10.2 | 10.2 | ### Example 3: Implement an upper cap using least **Goal**: Cap a value at a maximum threshold by using `least()` as an upper clamp. **XQL code**: ```sql config timeframe = 1d | dataset = sample_xql_raw | alter capped_duration = least(duration_seconds, 5.0) | fields event_id, duration_seconds, capped_duration | limit 3 ``` **Explanation**: This query ensures that `capped_duration` does not exceed `5.0` by returning the lesser of `duration_seconds` and `5.0`. Values above `5.0` are capped, while values below remain unchanged. **Output**: | EVENT\_ID | DURATION\_SECONDS | CAPPED\_DURATION | | --------- | ----------------- | ---------------- | | 101 | 1.5 | 1.5 | | 102 | 0.8 | 0.8 | | 103 | 10.2 | 5.0 | ## Related articles * **Stages**: [`alter`](/xql-command-reference-guide/readme/stages/alter.md), [`fields`](/xql-command-reference-guide/readme/stages/fields.md), [`limit`](/xql-command-reference-guide/readme/stages/limit.md) * **Functions**: [`greatest()`](/xql-command-reference-guide/readme/functions/greatest.md), `min_by()`, [`coalesce()`](/xql-command-reference-guide/readme/functions/coalesce.md) * **Datasets**: [`xdr_data`](https://docs-cortex.paloaltonetworks.com/r/Cortex-XQL-Schema-Reference-Guide/Introduction) --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. 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