存储过程中如何实现从数组获取数据

SET @array_content="6,6,41,43 12,12,43,45 1,1,41,45"; 

#获取数组长度
SET @count=CHAR_LENGTH(@array_content)-CHAR_LENGTH(REPLACE(@array_content,' ','')) + 1; 
#一维数组下标
SET @i=1 + FLOOR(RAND() * 3); 
#二维数组下标
SET @j=1 + FLOOR(RAND() * 4); 

set @randData = SUBSTRING_INDEX(SUBSTRING_INDEX(@array_content,' ',@i),' ',-1);

select SUBSTRING_INDEX(SUBSTRING_INDEX(@randData,',',@j),',',-1)