wm_concat(columnName),该函数可以把列值以","号分隔起来,并显示成一行
例 : 行转列
SQL> select wm_concat(name) from user; WM_CONCAT(NAME) ------------------------------------------------------------------------- i,am,b,o,a,t
原文：http://blog.csdn.net/helloboat/article/details/44645429