使用SQL时将多行合并为一行（一列）

Question

How to combine multiple rows into one row:

Example:
ID   NAME    NUMBER
24   infill  20
25   test1   10
26   test2   30
27   test5   35
28   test3   40

SELECT 
      name,
      number 
FROM table1 WHERE table1.id IN (24,26,28)

They will have result as:

NAME    NUMBER
infill  20
test2   30
test3   40

How to modify SQL statement above: and I have one column name as I really want.

Service

infill 20,test2 30, test3 40

I did:

select name + " " + number as Service 
from table1
where table1.id in (24,26,28)

Result is NULL, thank you all for reply my question.

Answer 1

You are close, the reason concat is not working since you aretrying to concat varchar with Int.

In order to concat, both the columns have to be of same datatype, try like this:

SELECT name + ' ' + Convert(nvarchar(max), number) AS Service 
FROM table1
WHERE table1.id IN (24,26,28)

Answer 2

Here is it

DECLARE @Str Varchar(max) = ''
SELECT @Str = @Str + Name + ' ' + CAST(Number As varchar) + ', ' AS Service FROM table1
WHERE table1.id in (24,26,28)
SELECT SUBSTRING(@Str, 0, LEN(@Str) - 2) AS Result

UPDATE:

More Simple

DECLARE @Str Varchar(max) 
SELECT @Str = COALESCE(@Str + ', ','') + Name + ' ' + CAST(Number As varchar) AS Service
FROM table1
WHERE table1.id in (24,26,28)
SELECT @Str AS Result

Answer 3

Try like this

  DECLARE @MyTable TABLE
  (
     ID     INT,
     NAME   VARCHAR(100),
     NUMBER INT
  )

INSERT INTO @MyTable
VALUES      (24,
             'infill',
             '20'),
            (25,
             'test1',
             '10'),
            (26,
             'test2',
             '30'),
            (27,
             'test5',
             '35'),
            (28,
             'test3',
             '40')

SELECT stuff((SELECT ',' + NAME + ' ' + CONVERT(VARCHAR(100), NUMBER)
              FROM   @MyTable
              WHERE  id IN ( 24, 26, 28 )
              FOR XML PATH('')), 1, 1, '') AS SERVICE