源数据是图书借阅的数据，是这样的：
"索书号","askno"
"K827/1171-92","91039114"
"K27/1806#2","91039114"
"I247.57/1098-3","13367927"
"I222.844.1/5974-2#1","93056856"
"I222.844.1/5974-2#2","93056856"
"I207.22/7217-3","93056856"
"I222.742.2/1121-2","93056856"
"I222.844.2/4436-1","93056856"
"O13-44/1212-5","13396006"
"TP3/1334-3","13396006"
"TP3/2224-16","13396006"
"O13-44/6854-1","13396006"
"O13/5667","13396006"
......


如何按照askno将索书号合并到同一行，即处理后每一行代表每次借阅的图书数据，像这样：


K827/1171-92,K27/1806#2
I247.57/1098-3
I222.844.1/5974-2#1,I222.844.1/5974-2#2,I207.22/7217-3,I222.742.2/1121-2,I222.844.2/4436-1
...


求教，感谢！