
Try the below

    select daily_user_count, count(*) from (
    SELECT COUNT(*) as daily_user_count FROM Activity
    GROUP BY entity_uid, date
    ) Z
    group by daily_user_count
    


I'd like to know how often a particular user does an activity on the same day



    SELECT COUNT(*) FROM Activity
    GROUP BY entity_uid, date

This returns a long lists of counts: i.e.

    1
    1
    2
    1

I'd then like to group the results of this query that tell me how often each number appears within the result set, like this

    #    Count(*)
    1    3
    2    1

Here's what I have, but it doesn't work



    Select x = (
                SELECT COUNT(*) FROM Activity
                GROUP BY entity_uid, date
               ),
           Count(*)
    GROUP BY x

How can I select the results of a subquery in a variable?

Group results of grouped query

Here's the [full list of reserved keywords][2] broken up by color:

[![Reserved Keywords by Color][1]][1]

**Operators** (Grey)  

ALL, AND, ANY, BETWEEN, CROSS, EXISTS, IN, INNER, IS, JOIN, LEFT, LIKE, NOT, NULL, OR, OUTER, PIVOT, RIGHT, SOME, UNPIVOT

**System Functions** (Magenta)  

COALESCE, COLLATE, CONTAINS, CONVERT, CURRENT_TIME, CURRENT_TIMESTAMP, CURRENT_USER, NULLIF, SESSION_USER, SYSTEM_USER, TSEQUAL, UPDATE

**Keywords** (Blue)  

ADD, ALTER, AS, ASC, AUTHORIZATION, BACKUP, BEGIN, BREAK, BROWSE, BULK, BY, CASCADE, CASE, CHECK, CHECKPOINT, CLOSE, CLUSTERED, COLUMN, COMMIT, COMPUTE, CONSTRAINT, CONTAINSTABLE, CONTINUE, CREATE, CURRENT, CURRENT_DATE, CURSOR, DATABASE, DBCC, DEALLOCATE, DECLARE, DEFAULT, DELETE, DENY, DESC, DISK, DISTINCT, DISTRIBUTED, DOUBLE, DROP, DUMP, ELSE, END, ERRLVL, ESCAPE, EXCEPT, EXEC, EXECUTE, EXIT, EXTERNAL, FETCH, FILE, FILLFACTOR, FOR, FOREIGN, FREETEXT, FREETEXTTABLE, FROM, FULL, FUNCTION, GOTO, GRANT, GROUP, HAVING, HOLDLOCK, IDENTITY, IDENTITYCOL, IDENTITY_INSERT, IF, INDEX, INSERT, INTERSECT, INTO, KEY, KILL, LINENO, LOAD, MERGE, NATIONAL, NOCHECK, NONCLUSTERED, OF, OFF, OFFSETS, ON, OPEN, OPENDATASOURCE, OPENQUERY, OPENROWSET, OPENXML, OPTION, ORDER, OVER, PERCENT, PLAN, PRECISION, PRIMARY, PRINT, PROC, PROCEDURE, PUBLIC, RAISERROR, READ, READTEXT, RECONFIGURE, REFERENCES, REPLICATION, RESTORE, RESTRICT, RETURN, REVERT, REVOKE, ROLLBACK, ROWCOUNT, ROWGUIDCOL, RULE, SAVE, SCHEMA, SECURITYAUDIT, SELECT, SET, SETUSER, SHUTDOWN, STATISTICS, TABLE, TABLESAMPLE, TEXTSIZE, THEN, TO, TOP, TRAN, TRANSACTION, TRIGGER, TRUNCATE, UNION, UNIQUE, UPDATETEXT, USE, USER, VALUES, VARYING, VIEW, WAITFOR, WHEN, WHERE, WHILE, WITH, WRITETEXT


  [1]: https://i.stack.imgur.com/FgAzI.png
  [2]: https://learn.microsoft.com/en-us/sql/t-sql/language-elements/reserved-keywords-transact-sql?view=sql-server-2017

Microsoft SQL Management Studio highlights some special words coloring them in blue or in pink. I would like to know which rule determines the color to use.

For example, consider the two following statements:

    SELECT * FROM myTable
    UPDATE myTable SET myFlag = 'X'


[![SELECT * FROM myTable UPDATE myTable SET myFlag = 'X'][1]][1]

`UPDATE` is in pink while `SET`, `SELECT`, & `FROM` are in in blue.


  [1]: https://i.stack.imgur.com/DdgtY.png