In our opinion, any Iterable<T> should offer a <R> collect(Collector<T, ?, R>) method to allow for transforming the the content to something else using standard JDK collectors, jOOλ collectors from org.jooq.lambda.Agg or your own. When using jOOQ, you don't have to wait for the JDK to finally add these useful utilities to the Iterable API. … Continue reading Use ResultQuery.collect() to Implement Powerful Mappings
Tag: grouping
How to Group By “Nothing” in SQL
The SQL standard knows a lesser known feature called GROUPING SETS. One particular side-effect of that feature is that we can group by "nothing" in SQL. E.g. when querying the Sakila database: SELECT count(*) FROM film GROUP BY () This will yield: count | ------| 1000 | What's the point, you're asking? Can't we just … Continue reading How to Group By “Nothing” in SQL
How SQL GROUP BY Should Have Been Designed – Like Neo4j’s Implicit GROUP BY
In the recent past, we've explained the syntactic implications of the SQL GROUP BY clause. If you haven't already, you should read our article "Do You Really Understand SQL’s GROUP BY and HAVING clauses?". In essence, adding a GROUP BY clause to your query transforms your query on very implicit levels. The following reminder summarises … Continue reading How SQL GROUP BY Should Have Been Designed – Like Neo4j’s Implicit GROUP BY