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This article focuses on "the nesting use of MySQL cursors". Interested friends may wish to have a look. The method introduced in this paper is simple, fast and practical. Now let the editor to take you to learn "the nesting use of MySQL cursors"!

A few days ago, someone in the group asked if MySQL cursors could be nested and took it for granted. Later, they tried it and found that it could, alas, not just take it for granted. Examples are as follows:

CREATE PROCEDURE curdemo ()

NOT DETERMINISTIC

CONTAINS SQL

SQL SECURITY DEFINER

COMMENT'

BEGIN

Declare done1,done2 int default 0

Declare name1,name2 varchar (20)

Declare id1,id2 int

Declare cur1 cursor for select id,name from test1

Declare continue handler for not found set done1 = 1

Open cur1

Repeat

Fetch cur1 into id1, name1

If not done1 then

Insert into test3 (name) values (name1)

Begin

Declare cur2 cursor for select id,name from test2

Declare continue handler for not found set done2 = 1

Open cur2

Repeat

Fetch cur2 into id2,name2

If not done2 then

Insert into test3 (name) values (name2)

End if

Until done2 end repeat

Close cur2

Set done2=0

End

End if

Until done1 end repeat

Close cur1

Commit

END

At this point, I believe you have a deeper understanding of the "nesting use of MySQL cursors". You might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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