substring_index(input,split,index)：input為要擷取的字元，split為分隔符，Index為要擷取第index個分隔符左（index為正）或右(index為負)的字串。

舉例：

"Provider="RiskManagement" finalScore="65" RGID="100397278"" //獲取finalScore的值

1、獲取finalScore右邊的字元

select substring_index("Provider="RiskManagement" finalScore="65" RGID="100397278"","finalScore="",-1);

2、再獲取" RGID="左邊的字元

select substring_index(substring_index("Provider="RiskManagement" finalScore="65" RGID="100397278"","finalScore="",-1),"" RGID="",1)。