Update row base on distinct, stuff, path query

问题

Continue from Combine multiple rows into one "memo" nvarchar(max)

SELECT
    DISTINCT fileref, stuff(
        (
        Select char(13)+char(10) + IsNull( D2.viaccno, '' )
        From vi_accno As D2
        Where D2.vifileref = A.FileRef
        For Xml Path(''), type
        ).value('.', 'nvarchar(max)')
        , 1, 2, '') As accno
FROM
   vtindex a

How do i use the above query to update each accno row on table 1 matching fileref = fileref

table 1: id, fileref, client, addr, accno

回答1:

Based on given data, I can offer you this:

UPDATE t
SET accno = p.accno 
FROM [table 1] t
INNER JOIN (
SELECT
    DISTINCT fileref, stuff(
        (
        Select char(13)+char(10) + IsNull( D2.viaccno, '' )
        From vi_accno As D2
        Where D2.vifileref = A.FileRef
        For Xml Path(''), type
        ).value('.', 'nvarchar(max)')
        , 1, 2, '') As accno
FROM
   vtindex a
) as p
ON p.fileref= t.fileref

来源：https://stackoverflow.com/questions/38093988/update-row-base-on-distinct-stuff-path-query