Group By

GROUP BY collapses the selected documents into one row for each distinct combination of the grouped fields or expressions. Fields that are not grouped can only be used inside Aggregate Functions.
When a query uses aggregate functions without GROUP BY, all of the selected documents form a single group. HAVING is not supported.

Groups the synonyms by source word and computes several aggregates.

SELECT
    SourceWordId,
    Min(TargetWordId) as Min,
    Max(TargetWordId) as Max,
    Sum(TargetWordId) as Sum,
    Avg(TargetWordId) as Avg,
    Count(TargetWordId) as Count
FROM
    WordList:Synonym
GROUP BY
    SourceWordId

Counts the words of each language, largest first.

SELECT
    LanguageId,
    Count(0) as Words
FROM
    WordList:Word
GROUP BY
    LanguageId
ORDER BY
    Count(0) DESC

Aggregates without GROUP BY.

SELECT Count(0) as Words, Min(Id) as FirstId, Max(Id) as LastId FROM WordList:Word

• Aggregate Functions
• Distinct