Select the database ()
And why
Select (select (database ()))
The results, and can be stacked innumerable select

CodePudding user response:

This may be a matter of time

CodePudding user response:

Select (select (database ())) content in brackets, the outermost layers of the one of you can understand as a mysql table, no matter in or out superposition of N layer, is the principle of theory and logic, is like this,