MySql5.6 JSON解析 根据key 取值

-- fs_pay_info json 字符串
-- "90003": key 

-- SUBSTRING(str,index,length)
-- LOCATE(subStr,str,startIndex)

SUBSTRING(fs_pay_info,LOCATE('"90003":',fs_pay_info)+8,IF(LOCATE(',',fs_pay_info,2) =0,LOCATE('}',fs_pay_info,2),LOCATE(',',fs_pay_info,2))-(LOCATE('"90003":',fs_pay_info)+8)) AS freeamnt