I have table which have 20 million records . I have recently added another column to that table. I need to update the data into that column. I’m using MYSQL community edition, when I execute the direct update like this :

Update Employee SET Emp_mail = 'xyz_123@gmail.com'

System Getting hanged and Need to close the execution abruptly. But when I update the statement with filter condition it is executing fine.

Update Employee SET Emp_mail = 'xyz_123@gmail.com' where ID <= 10000;
Update Employee SET Emp_mail = 'xyz_123@gmail.com' where ID >= 10000 AND ID <= 10000 ;

--------
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no of  Times

Now I’m looking for looping script where I can execute in chunk wise.

For example in SQL it is like this but I’m not sure of MYSQL:

BEGIN 
I int = 0 ;
cnt = 0 ;
while 1 > cnt
SET  i = i + 1; 
Update Employee SET Emp_mail = 'xyz_123@gmail.com' where ID >= cnt AND ID <= I

END

Note : this is a random script syntax wise there may be some errors . Please ignore it.

I’m looking for Looping in MYSQL