Why MySQL nested Cursor fetch always return the Parent Cursor's first values?

updateMatchedAddress.sql

CREATE DEFINER = 'geocodingdb'@'%'
PROCEDURE geocodingdb.updateMatchResult()
BEGIN 
  DECLARE done1 int default false;  
  DECLARE bizId nvarchar(64);

  # 定义光标 where  source_address_id='001A866D0F5647B5A74530EF8CF8AAFA'  
  DECLARE cursor_bizId CURSOR FOR
          select source_address_id  FROM geocodingdb.MatchedAddressGroupbySkeleton 
          where  source_address_id IN ('001A866D0F5647B5A74530EF8CF8AAFA','000032E78F5E4F65A2C75DAEAF53B62E')   GROUP BY source_address_id;
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done1 = TRUE; 

  /* 打开光标 */
  OPEN cursor_bizId;
  # 循环获取业务ID  
  loop_getBizId:LOOP
     FETCH cursor_bizId INTO bizId; 
      IF done1 THEN
        LEAVE loop_getBizId;
        /*关闭光标*/
        CLOSE cursor_bizId;
      END IF; 
  
    # 根据业务ID获取匹配地址
    block_matchedAddress:BEGIN 
        DECLARE _rownum int;
        DECLARE _matchID nvarchar(64);
        DECLARE _matchedType nvarchar(8);
        DECLARE _matchedAddress nvarchar(3000);
        DECLARE _x,_y decimal(11, 6); 
      
        DECLARE done2 int default false; 
        #cursor:获取匹配地址（由于是动态select语句，故从视图中间接查询）
        DECLARE cursor_matchedAddress CURSOR FOR SELECT * FROM temp_matchedAddress; 
        DECLARE continue handler for not found set done2 = true;  

        #新建视图temp_maxAddressNodeOrder存储 匹配地址中最深地址路径
        SET @sql_query_maxAddressNodeOrder=  CONCAT("(SELECT  MAX(o1.AddressNodeOrder) AS deepSize, matched_address_type    FROM MatchedAddressGroupbySkeleton t1 LEFT JOIN AddressNodeOrder o1   ON t1.matched_address_type = o1.addressNode  
                                 WHERE source_address_id='",bizId  COLLATE utf8_unicode_ci ,"')"); 
        SET @query_maxAddressNodeOrder = CONCAT('CREATE OR REPLACE  view  temp_maxAddressNodeOrder as ', @sql_query_maxAddressNodeOrder);  
        PREPARE stmt from @query_maxAddressNodeOrder; 
        EXECUTE stmt; 
        DEALLOCATE PREPARE stmt;  
    
        #新建视图temp_maxAddressNodeOrder存储 匹配地址（多个）
        SET @temp_rowNumber=0;
        SET @sql_query_matchedAddress= concat("SELECT  getRowNum() AS _rownum, matched_address_id AS _matchID, matched_address_type AS _matchedType, matched_address AS _matchedAddress, longitude AS _x, latitude AS _y 
          FROM MatchedAddressGroupbySkeleton t3 WHERE t3.source_address_id='",bizId  COLLATE utf8_unicode_ci ,"' AND t3.matched_address_type = 
              (SELECT  matched_address_type  FROM temp_maxAddressNodeOrder AS t2)"); 
        SET @query_matchedAddress = CONCAT('CREATE OR REPLACE  view  temp_matchedAddress as ', @sql_query_matchedAddress);  
        PREPARE stmt from @query_matchedAddress; 
        EXECUTE stmt; 
        DEALLOCATE PREPARE stmt;  
      
        OPEN cursor_matchedAddress;  
        # 循环获取匹配地址
        loop_getMatchedAddress:LOOP  
            #XXX FETCH Into的结果总是父级Cursor(cursor_bizId)的第一个bizId的查询结果！why?
            FETCH cursor_matchedAddress INTO _rownum, _matchID, _matchedType, _matchedAddress, _x, _y;
            
            IF done2 THEN
               LEAVE loop_getMatchedAddress;
               CLOSE cursor_matchedAddress;
            END IF;
            # 根据当前循环的rownum，更新指定候选匹配地址字段
            # rownum=1时，更新4个匹配结果字段；rownumber=n时，更新字段<候选匹配地址n>
            IF _rownum = 1 THEN 
               update 地名地址整合数据源表 set 匹配ID=_matchID,匹配精度=_matchedType,匹配地址=_matchedAddress,地址经度=_x,地址纬度=_y where 业务ID=bizId   COLLATE utf8_unicode_ci;
            ELSE
               SET @matchedAddressField = CONCAT("候选匹配地址", _rownum - 1);
               #MySQL5.7.8支持JSON序列化，暂用版本5.5，手动序列化
               # SET @matchedAddress=JSON_ARRAY(匹配精度,匹配地址,地址经度,地址纬度,匹配ID);
               SET @matchedAddress = CONCAT_WS(" | ", _matchedType, _matchedAddress,_x,_y, _matchID); 
               SET @sql = CONCAT("update 地名地址整合数据源表 SET ", @matchedAddressField, "='", @matchedAddress, "' where 业务ID='", bizId COLLATE utf8_unicode_ci,"'"); 
               PREPARE stmt from  @sql;
               EXECUTE stmt;
               DEALLOCATE PREPARE stmt; 

            END IF;
        END LOOP loop_getMatchedAddress;
  
      END block_matchedAddress;
  
  END LOOP loop_getBizId;


END

FETCH Into的结果总是父级Cursor(cursor_bizId)的第一个bizId的查询结果！why?
View的问题，换成temporary table，已解决，见gist