The database queries n rows to 1 rows

First, create a sample table

CREATE TABLE testtable (name VARCHAR (ten), skill varchar), insert into TestTable VALUES (' Zhang San ', ' php '); INSERT INTO Testtab Le values (' Zhang San ', ' Java '), insert into testtable values (' Zhang San ', ' C # '), insert into testtable values (' John Doe ', ' C '); INSERT INTO Te Sttable VALUES (' John Doe ', ' C + + ');

The table structure is:

Name	Skill
Tom	Php
Tom	Java
Tom	C#
John doe	C
John doe	C++

The result of the desired query:

Name	Allskill
Tom	php,java,c#
John doe	C,c++

Second, implement in SQL Server

--SQL Serverselect Name,stuff (   (   SELECT ', ' + skill from   testtable a   WHERE a.name = b.name for   XML PA TH (")   ),   1, 1, ') as Allskillfrom testtable bgroup by name

Third, the implementation of MySQL

--Mysqlselect Name,group_concat (skill) as Allskillfrom testtablegroup by name;

IV. implementation in Oracle

--Oracleselect Name,wmsys. Wm_concat (skill) as Allskillfrom testtablegroup by name;

　　

The database queries n rows to 1 rows