python - SQLAlchemy - Handling Constraint Failures -

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with sqlalchemy, if have unique column in database eg, username:

username = db.column(db.string(50), unique=true)

when add row breaks constraint username i’m trying add exists, integrityerror thrown:

integrityerror: (integrityerror) (1062, u"duplicate entry 'test' key 'username'")

is possible instead map breaking of constraint custom exception? eg.usernameexistserror

i want able catch individual constraint breaks, , send response user. eg: "this username in use"

is possible? or next best thing?

any guidance appreciated :)

the next best thing might surrounding call try ... except, parsing error message, , notifying user constructed error message.

along lines, try ... except error , return custom error code flask's custom error pages.


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