Aggregate combinators examples #3446
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…n favour of only the most common ones
…into aggregate_combinators_examples_most_popular
…into aggregate_combinators_examples_most_popular
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| FROM sales; | ||
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| The `avgIf` function will calculate the average amount only for rows where `is_successful = 1`. |
| ``` | ||
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| Let's get the average wage of the people whose age lies in the intervals of `[30,60)` | ||
| and `[60,75)`. Since we use integer representation for age, we get ages in the |
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is ) meant to imply inclusive?
| ('Brian', 60, 16.0); | ||
| ``` | ||
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| Let's count all the people whose age lies in the intervals of `[30,60)` |
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ok i assume same as above
| GROUP BY URLDomain | ||
| ORDER BY URLDomain ASC | ||
| LIMIT 20; | ||
| ``` |
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add to sql.clickhouse.com repo please!
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| The [`SimpleState`](/sql-reference/aggregate-functions/combinators#-simplestate) combinator can be applied to the [`min`](/sql-reference/aggregate-functions/reference/min) | ||
| function to return the minimum value across all input values. It returns the | ||
| result with type `SimpleAggregateState`. |
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link to SimpleAggregateState and maybe say we simple is useful (i.e. its lighter than full aggregatestate but limited to certain functions)
| ```sql | ||
| SELECT | ||
| post_id, | ||
| sumSimpleState(upvotes) AS total_upvotes, |
| Create a materialized view with `SimpleAggregateFunction` type columns: | ||
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| ```sql | ||
| CREATE MATERIALIZED VIEW vote_totals |
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create aggregate table seperately from MV for best practice
| SELECT | ||
| post_id, | ||
| sumSimpleState(upvotes) AS total_upvotes, | ||
| sumSimpleState(downvotes) AS total_downvotes, |
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not sure we need these sumSimpleState
| When you use `sumSimpleState(column)`: | ||
| - It directly extracts the stored sum value without doing any additional | ||
| aggregation. | ||
| - The result is of type `SimpleAggregateFunction(sum, Int64)` |
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this doesnt make sense, why do this?
| AS | ||
| SELECT | ||
| post_id, | ||
| toUInt32(vote_type = 'upvote') AS upvotes, |
Summary
Adds examples of common aggregate function combinator functions.
Checklist