问题
hi everyone i'm à newbie in uml and my question is simple:i want to draw a sequence diagram for members login and the steps are as follows:
the member visits the login page
enters email/pwd
clicks login
then the system goes to the database
if record exists
if account active
display login success msg
else (account not active)
display error msg
else(record does not exists)
display error msg
and the diagram should contains the following objects:
member
login page
System
database
so can any one show me how it's done and thanks in advance.
回答1:
The best is simply not to use a sequence diagram for things which are better expressed in code like if and loop. However, if there is a need for it, use fragments and put the according sections inside.
See here for examples.
Your case will start looking like this:
来源：https://stackoverflow.com/questions/29962262/need-help-in-a-login-sequence-diagram