我结束了下面列出的过程.它可以工作，但是我不确定所有查询来识别连续范围是否有效.可以使用以下参数(示例)来调用它:

I ended up with the procedure listed below. It works but I am not sure whether it is efficient with all the queries to identify consecutive ranges. It can be called with the following arguments (example):

call chunkUpdate('SET var=0','someTable','theKey',500000);

基本上，第一个参数是更新命令(例如"set x = ..."之类的命令)，其后是mysql表名，其后是必须唯一的数字(整数)键，然后是要处理的块的大小.密钥应具有合理性能的索引.可以删除下面代码中的"n"变量和"select"语句，仅用于调试.

Basically, the first argument is the update command (e.g. something like "set x = ..."), followed by the mysql table name, followed by a numeric (integer) key that has to be unique, followed by the size of the chunks to be processed. The key should have an index for reasonable performance. The "n" variable and the "select" statements in the code below can be removed and are only for debugging.

delimiter //
CREATE PROCEDURE chunkUpdate (IN cmd VARCHAR(255), IN tab VARCHAR(255), IN ky VARCHAR(255),IN sz INT)
BEGIN
  SET @sqlgetmin = CONCAT("SELECT MIN(",ky,")-1 INTO @minkey FROM ",tab); 
  SET @sqlgetmax = CONCAT("SELECT MAX(",ky,") INTO @maxkey FROM ( SELECT ",ky," FROM ",tab," WHERE ",ky,">@minkey ORDER BY ",ky," LIMIT ",sz,") AS TMP"); 
  SET @sqlstatement = CONCAT("UPDATE ",tab," ",cmd," WHERE ",ky,">@minkey AND ",ky,"<=@maxkey");
  SET @n=1;

  PREPARE getmin from @sqlgetmin;
  PREPARE getmax from @sqlgetmax;
  PREPARE statement from @sqlstatement;

  EXECUTE getmin;

  REPEAT
    EXECUTE getmax; 
    SELECT cmd,@n AS step, @minkey AS min, @maxkey AS max;
    EXECUTE statement;
    set @minkey=@maxkey;
    set @n=@n+1;
  UNTIL @maxkey IS NULL
  END REPEAT; 
  select CONCAT(cmd, " EXECUTED IN ",@n," STEPS") AS MESSAGE;
END//