SQL Query multiple users who started on the same date

Question

I've got a table something like this:

UserID  TeamID  StartedDate
36202   1213    27/11/2019 9:00
36203   1213    1/11/2019 10:30
36203   1207    24/11/2019 10:00
36205   1207    21/11/2019 9:15
36203   1213    1/11/2019 10:30
36214   1217    10/11/2019 10:00
36205   1207    24/11/2019 10:00
36202   1213    1/11/2019 10:30

How do I query a list of users who have the same "StartedDate" for each unique date?

Output should be look like this.

StartedDate         UserID's
24/11/2019 10:00    36203 & 36205
1/11/2019 10:30     36202 & 36203

I need to ignore time & focus on the date only.

Answer 1

You can achieve it by this way, Live demo here

SELECT DISTINCT C2.StartedDate, 
SUBSTRING(
(
   SELECT ', ' + CAST(C1.UserID AS VARCHAR(20))
   FROM TempTable C1
   WHERE C1.StartedDate = C2.StartedDate
  ORDER BY C1.StartedDate
  FOR XML PATH ('')
), 2, 1000) AS "UserList"
FROM TempTable C2

Output

StartedDate          UserList
1/11/2019 10:30      36203, 36203, 36202
10/11/2019 10:00     36214
21/11/2019 9:15      36205
24/11/2019 10:00     36203, 36205
27/11/2019 9:00      36202

Answer 2

Try this:

DECLARE @DataSource TABLE
(
    [UserID] INT
   ,[TeamID] INT
   ,[StartedDate] VARCHAR(24)
);

INSERT INTO @DataSource ([UserID], [TeamID], [StartedDate])
VALUES (36202, 1213,  '27/11/2019 9:00')
      ,(36203, 1213,  '1/11/2019 10:30')
      ,(36203, 1207,  '24/11/2019 10:00')
      ,(36205, 1207,  '21/11/2019 9:15')
      ,(36203, 1213,  '1/11/2019 10:30')
      ,(36214, 1217,  '10/11/2019 10:00')
      ,(36205, 1207,  '24/11/2019 10:00')
      ,(36202, 1213,  '1/11/2019 10:30');

-- SQL Server 2017+
SELECT [StartedDate]
      ,STRING_AGG([UserID], ',') AS [UserID's]
FROM
(
    SELECT DISTINCT [StartedDate]
                   ,[UserID]
    FROM @DataSource
) DS
GROUP BY [StartedDate];

-- SQL Server
WITH DataSoruce AS
(
    SELECT DISTINCT [StartedDate]
    FROM @DataSource
)
SELECT *
FROM DataSoruce A
CROSS APPLY
(
    SELECT STUFF
    (
        (
            SELECT DISTINCT ',' + CAST([UserID] AS VARCHAR(12))
            FROM @DataSource S
            WHERE A.[StartedDate] = S.[StartedDate]
            FOR XML PATH, TYPE 
        ).value('.', 'VARCHAR(MAX)')
        ,1
        ,1
        ,''
    )
) R ([UserID's])