


How Do `FOR XML PATH` and `STUFF` Combine to Concatenate Data in SQL Server?
The synergy of FOR XML PATH and STUFF functions in SQL Server
In SQL Server, the combination of FOR XML PATH
and STUFF
functions play a vital role in organizing and joining data. Let’s break down its mechanics to achieve the desired goal:
1. Use 'FOR XML PATH' to extract XML element string
FOR XML PATH
Convert query results into XML elements. By omitting the element name, it outputs a comma-separated list of values, as shown in the example:
SELECT ',' + name FROM temp1 FOR XML PATH('')
2. Use STUFF to remove leading commas
STUFF
is used to modify a string by replacing specified characters. In this example, we remove the leading comma in the XML string:
STUFF((SELECT ',' + NAME FROM temp1 FOR XML PATH('')), 1, 1, '')
3. Perform join to generate list
Finally, the modified list is joined with the original table via the 'id' column:
SELECT ID, abc = STUFF(( SELECT ',' + name FROM temp1 t1 WHERE t1.id = t2.id FOR XML PATH ('')) , 1, 1, '') from temp1 t2 group by id;
This combination effectively concatenates the 'Name' column values for each 'Id' , resulting in the expected output:
<code>Id | Name ------------------- 1 | aaa,bbb,ccc,ddd,eee</code>
The above is the detailed content of How Do `FOR XML PATH` and `STUFF` Combine to Concatenate Data in SQL Server?. For more information, please follow other related articles on the PHP Chinese website!

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