Sc table:

Student table:

I modified statement:

 set the update sc grade='0' where sno in (select sno from student where sdept='cs'); 

Change as a result, the failure did not respond, why:

CodePudding user response:

How to perform, cut in figure come up

CodePudding user response:

Directly execute the command:

CodePudding user response:

This update has not yet been submitted, in another session to check?

CodePudding user response:

Here, there is a influence the number of rows, is it? If 2 rows, you can submit the reference # 2's advice,

CodePudding user response:

1, you behind the update query sc table to see if there is any change data directly,
2, if the query in the other session, so behind the update after the commit point, in the other session again query,

CodePudding user response:

After execution to here will be bright, remember, this update is complete

CodePudding user response:

Commit;

CodePudding user response:

The update should be a session, no commit; Another session of the query