The HAVING clause filters grouped results or aggregation results.
Syntax
HAVING bool_expression-
The HAVING clause filters aggregation results, whereas the WHERE clause filters raw data before aggregation.
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The HAVING clause is evaluated after the GROUP BY clause and before the ORDER BY clause.
Parameters
|
Parameter |
Description |
|
bool_expression |
A Boolean expression. |
Examples
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Example 1: Return the request URIs with an average request duration greater than 40 seconds.
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Query statement
* | SELECT avg(request_time) AS avg_time, request_uri GROUP BY request_uri HAVING avg(request_time) > 40 -
Query and analysis result: The result lists the avg_time and request_uri for URIs where the average request duration is greater than 40 seconds.
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Example 2: Query service logs to find Projects with a write latency greater than 1,000 microseconds.
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Query statement
* | SELECT avg(latency) AS avg_latency, Project GROUP BY Project HAVING avg_latency > 1000 -
Query and analysis result: The query returns one row, showing an avg_latency of
1569.909090909091for the corresponding Project name, which confirms that the average latency is greater than 1,000.
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