Can I Comma Delimit Multiple Rows Into One Column?

问题:

This question already has answers here:

How to concatenate text from multiple rows into a single text string in SQL server? (47 answers)

Closed 4 years ago.

I am attempting to merge something like this in my SQL Server database:

[TicketID], [Person]
 T0001       Alice
 T0001       Bob
 T0002       Catherine
 T0002       Doug
 T0003       Elaine

Into this:

[TicketID], [People]
 T0001       Alice, Bob
 T0002       Catherine, Doug
 T0003       Elaine

I need to do this in both SQL Server and Oracle.

I have found the function GROUP_CONCAT for MySQL that does exactly what I need here, but MySQL is not an option here.

EDIT: Test bench:

DECLARE @Tickets TABLE (
    [TicketID] char(5) NOT NULL,
    [Person] nvarchar(15) NOT NULL
)

INSERT INTO @Tickets VALUES
    ('T0001', 'Alice'),
    ('T0001', 'Bob'),
    ('T0002', 'Catherine'),
    ('T0002', 'Doug'),
    ('T0003', 'Elaine')

SELECT * FROM @Tickets

回答1:

Here is a solution that works in SQL Server 2005+:

SELECT t.TicketID,
       STUFF(ISNULL((SELECT ', ' + x.Person
                FROM @Tickets x
               WHERE x.TicketID = t.TicketID
            GROUP BY x.Person
             FOR XML PATH (''), TYPE).value('.','VARCHAR(max)'), ''), 1, 2, '') [No Preceeding Comma],
       ISNULL((SELECT ', ' + x.Person
                FROM @Tickets x
               WHERE x.TicketID = t.TicketID
            GROUP BY x.Person
             FOR XML PATH (''), TYPE).value('.','VARCHAR(max)'), '') [Preceeding Comma If Not Empty]
  FROM @Tickets t
GROUP BY t.TicketID

Reference:

• STUFF (Transact-SQL)

回答2:

And, the MySQL version, for completeness:

select
    TicketId,
    GROUP_CONCAT(Person ORDER BY Person SEPARATOR ', ') People
from
    table
group by
    TicketId

回答3:

DECLARE @Tickets TABLE (
    [TicketID] char(5) NOT NULL,
    [Person] nvarchar(15) NOT NULL
)
INSERT INTO @Tickets VALUES
    ('T0001', 'Alice'),
    ('T0001', 'Bob'),
    ('T0002', 'Catherine'),
    ('T0002', 'Doug'),
    ('T0003', 'Elaine')

SELECT * FROM @Tickets

Select [TicketID],
STUFF((SELECT ',' + Person FROM @Tickets WHERE (
TicketID=Result.TicketID) FOR XML PATH ('')),1,1,'') AS BATCHNOLIST
From @Tickets AS Result
GROUP BY TicketID

回答4:

I have found a way to do this in Oracle, but I still need to do it in SQL Server.

From http://technology.amis.nl/blog/6118/oracle-rdbms-11gr2-listagg-new-aggregation-operator-for-creating-comma-delimited-strings (Thanks tanging) (ORACLE 11 and up)

select
    TicketId,
    listagg(Person, ', ') People
from
    table
group by
    TicketId

From: http://halisway.blogspot.com/2006/08/oracle-groupconcat-updated-again.html

with
    data
as
  (
    select
        TicketId,
        Person,
        ROW_NUMBER() over (partition by TicketId order by Person) "rownum",
        COUNT(*) over (partition by TicketId) "count"
    from
        Table
  )
select
    TicketId,
    LTRIM(sys_connect_by_path(Person,','),',') People
from
    data
where
    "rownum" = "count"
start with
    "rownum" = 1
connect by
    prior TicketId = TicketId
  and
    prior "rownum" = "rownum" - 1
order by
    TicketId

回答5:

one example

SELECT DISTINCT
    t.TicketID,
    STUFF((SELECT ', ', i.Person as [text()]
           FROM @Tickets i 
           WHERE i.TicketID = t.TicketID
           FOR XML PATH ('')), 1, 2, '') as People
FROM
    @Tickets t

......... or try ..............

SELECT DISTINCT
    t.TicketID,
    STUFF((SELECT ', ' + i.Person    /* notice this line is different */
           FROM @Tickets i 
           WHERE i.TicketID = t.TicketID
           FOR XML PATH ('')), 1, 2, '') as People
FROM
    @Tickets t

/* this works when I used this for my table and credit goes to my manager that ROCKS! */