在Oracle中則可以使用wm_concat 或 ListAgg

01.CREATE TABLE MyTest(xType NUMBER,City nvarchar2(200));  
02./  
03.  
04.INSERT INTO MyTest(xType,City)  
05.SELECT 1,'北京' FROM dual UNION ALL  
06.SELECT 1,'上海' FROM dual UNION ALL  
07.SELECT 1,'廣州' FROM dual UNION ALL  
08.SELECT 2,'武漢' FROM dual UNION ALL  
09.SELECT 2,'杭州' FROM dual UNION ALL  
10.SELECT 2,'廈門' FROM dual  
11.COMMIT;  
 

使用wm_Concat:

SELECT xType,wmsys.wm_concat(to_char(City)) AS xCity FROM MyTest GROUP BY xType 

使用ListAgg:

SELECT xType, ListAgg(to_char(City),',') WITHIN GROUP(ORDER BY xType) AS xCity FROM MyTest GROUP BY xType  

XTYPE          XCITY
----------   --------------------------------------
         1        北京,廣州,上海
         2         杭州,武漢,廈門