DS-15647 DS-15648: Document aggregate-if and date/time function additions to the WAE SQL API (#26101)

* DS-15647 DS-15648: Document aggregate-if and date/time function additions to the WAE SQL API

This commit adds the following function additions to the docs:

- `countIf`
- `sumIf`
- `avgIf`
- `toYear`
- `toMonth`
- `toDayOfMonth`
- `toHour`
- `toMinute`
- `toSecond`
- `toStartOfYear`
- `toStartOfMonth`
- `toStartOfDay`
- `toStartOfHour`
- `toStartOfFifteenMinutes`
- `toStartOfMinute`
- `today`

This commit reorders the date/time docs page to be in approximate alphabetical
order, which works much better than just appending the functions to the end.

* DS-15648: Document further date/time function additions to the WAE SQL API

These are some assorted functions commonly used by LLMs:

  - `toDayOfWeek`
  - `toStartOfWeek`
  - `toStartOfTenMinutes`
  - `toStartOfFiveMinutes`
  - `toYYYYMM`

* Add changelog for further WAE SQL additions

This commit adds a changelog entry for recent function additions,
as documented in the previous commits.

I have chosen to omit descriptions of the date/time functions,
because they are all quite generic and it looks unwieldy to have
some many samey descriptions.

* Update src/content/changelog/workers/2025-11-12-analytics-engine-further-sql-enhancements.mdx

Co-authored-by: Brendan Irvine-Broque <[email protected]>

---------

Co-authored-by: Brendan Irvine-Broque <[email protected]>

Author: 46bit

src/content/changelog/workers/2025-11-12-analytics-engine-further-sql-enhancements.mdx

@@ -0,0 +1,40 @@
+---
+title: More SQL aggregate, date and time functions available in Workers Analytics Engine
+description: Workers Analytics Engine now supports more SQL functions for aggregation and for working with dates and times
+date: 2025-11-12
+products:
+  - workers-analytics-engine
+---
+You can now perform more powerful queries directly in [Workers Analytics Engine](https://developers.cloudflare.com/analytics/analytics-engine/) with a major expansion of our SQL function library.
+
+Workers Analytics Engine allows you to ingest and store high-cardinality data at scale (such as custom analytics) and query your data through a simple SQL API. 
+
+Today, we've expanded Workers Analytics Engine's SQL capabilities with several new functions: 
+
+[**New aggregate functions:**](https://developers.cloudflare.com/analytics/analytics-engine/sql-reference/aggregate-functions/)
+- `countIf()` - count the number of rows which satisfy a provided condition
+- `sumIf()` - calculate a sum from rows which satisfy a provided condition
+- `avgIf()` - calculate an average from rows which satisfy a provided condition
+
+[**New date and time functions:**](https://developers.cloudflare.com/analytics/analytics-engine/sql-reference/date-time-functions/)
+- `toYear()`
+- `toMonth()`
+- `toDayOfMonth()`
+- `toDayOfWeek()`
+- `toHour()`
+- `toMinute()`
+- `toSecond()`
+- `toStartOfYear()`
+- `toStartOfMonth()`
+- `toStartOfWeek()`
+- `toStartOfDay()`
+- `toStartOfHour()`
+- `toStartOfFifteenMinutes()`
+- `toStartOfTenMinutes()`
+- `toStartOfFiveMinutes()`
+- `toStartOfMinute()`
+- `today()`
+- `toYYYYMM()`
+
+## Ready to get started? 
+Whether you're building usage-based billing systems, customer analytics dashboards, or other custom analytics, these functions let you get the most out of your data. [Get started ](/analytics/analytics-engine/get-started/) with Workers Analytics Engine and explore all available functions in our [SQL reference documentation](/analytics/analytics-engine/sql-reference/). 

src/content/docs/analytics/analytics-engine/sql-reference/aggregate-functions.mdx

@@ -248,3 +248,57 @@ SELECT topKWeighted(double1, _sample_interval) FROM my_dataset
 -- find the 15 most common values of <blob1>, weighted by `_sample_interval`
 SELECT topKWeighted(15)(blob1, _sample_interval) FROM my_dataset
 ```
+
+## countIf <Badge text="New" variant="tip" size="small" />
+
+Usage:
+
+```sql
+countIf(<expr>)
+```
+
+`countIf` is an aggregation function that returns the number of rows in the results set,
+but only counting rows where a provided expression evaluates to true.
+
+Example:
+
+```sql
+-- return the number of rows where `double1` is greater than 5
+countIf(double1 > 5)
+```
+
+## sumIf <Badge text="New" variant="tip" size="small" />
+
+Usage:
+
+```sql
+sumIf(<expr>, <expr>)
+```
+
+`sumIf` is an aggregation function that returns the sum of a first expression across all rows in the results set,
+but only including rows where a second expression evaluates to true.
+
+Example:
+
+```sql
+-- return the sum of column `item_cost` of all items where another column `in_stock` is not zero
+sumIf(item_cost, in_stock > 0)
+```
+
+## avgIf <Badge text="New" variant="tip" size="small" />
+
+Usage:
+
+```sql
+avgIf(<expr>, <expr>)
+```
+
+`avgIf` is an aggregation function that returns the mean of an expression across all rows in the results set,
+but only including rows where a second expression evaluates to true.
+
+Example:
+
+```sql
+-- return the mean of column `item_cost` where another column `in_stock` is not zero
+avgIf(item_cost, in_stock > 0)
+```