Oracle 解析json串中的数据

		select substr(aj.join_desc,instr(aj.join_desc,'"groupName":"')+length('"groupName":"'),
		       length(substr(aj.join_desc,instr(aj.join_desc,'"groupName":"')++length('"groupName":"')))
					 -length(substr(substr(aj.join_desc,instr(aj.join_desc,'"groupName":"')++length('"groupName":"')),
					 instr(substr(aj.join_desc,instr(aj.join_desc,'"groupName":"')++length('"groupName":"')),'","'))))
		 from 
		(
		select '{"upNum":"0","groupName":"123456789","hide":"N","nickName":"(-.-)瑄","groupKey":"notGroupKey","graden":"1","headUrl":"https://thirdwx.qlogo.cn/mmopen/vi_32/ibNBfuaaQydysYwpn521OPOtAEibAVv0Zorv8NPaXfukeMAUoh9J25DJlw9Dsjathml9giaLLIK75pMqBfCoYzM7g/132"}' as join_desc from dual
		) aj