Stored procedures cursor cursor

Stored procedure cursors, in fact, the result set, and then want to manipulate the result set of data, the cursor can be read line by line

First declare a cursor

delimiter $$
CREATE procedure changeName()
begin
declare stopflag int default 0;
declare myname varchar(20) default '';
declare my_cursor cursor for select sname from student where sid%2=0;
declare continue handler for not found set stopflag=1;
open my_cursor;
while(stopflag=0) do
begin
fetch my_cursor into myname;
update student set sname = concat(sname,'aab') where sname = myname;
end;
end while;
close my_cursor;
end;
$$

The above is the use of a cursor,

important point:

Cursor declaration need after all other variables, cursors often cooperate to achieve a state value, we need to declare a stop identity

declare continue handler for not found set identifier repose = 1;

Use the cursor first open, finally we need to close

Pick-fetch my_cursor into a cursor variable values