entity relationship - Creating the ER Model after the creation fo the database -


i've created program runnning on web (html) booking tickets on cinema theater.

i want create er model.

as far know, logical sequence of actions is:

  1. create er model
  2. generate physical model
  3. create database

so now, when try create er model, relation between entities doesn't seem right. on other hand, if add more entities customer or admin, means have created more tables database don't need.

anyone can me in one?


-

Comments

Post a Comment

Popular posts from this blog

go - Idiomatic way to handle template errors in golang -

say have html/template following: <html> <body> <p>{{somefunc .somedata}}</p> </body> and somefunc returns error. there idiomatic way deal this? if write directly responsewriter , status code 200 has been written before encounter error. var tmpl *template.template func handler(w http.responsewriter, r *http.request) { err := tmpl.execute(w, data) // "<html><body><p>" has been written... // err? } preferably return status code 400 or such, can't see way if use template.execute directly on responsewriter . there i'm missing? since template engine generates output on-the-fly, parts of template preceding somefunc call sent output. , if output not buffered, (along http 200 status) may sent. you can't that. what can perform check before call template.execute() . in trivial case should enough call somefunc() , check return value. if choose path , return value of somefunc() c...
Read more

python - Creating a new virtualenv gives a permissions error -

i'm getting following output when running virtualenv newvenv . traceback (most recent call last): file "/usr/local/bin/virtualenv", line 5, in <module> pkg_resources import load_entry_point file "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2727, in <module> add_activation_listener(lambda dist: dist.activate()) file "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 700, in subscribe callback(dist) file "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2727, in <lambda> add_activation_listener(lambda dist: dist.activate()) file "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2227, in activate self.insert_on(path) file "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2334, in insert_on self.check_version_conflict() file "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2373, in check_version_conflict...
Read more

c# - What is a NullReferenceException, and how do I fix it? -

i have code , when executes, throws nullreferenceexception , saying: object reference not set instance of object. what mean, , can fix error? what cause? bottom line you trying use null (or nothing in vb.net). means either set null , or never set @ all. like else, null gets passed around. if null in method "a", method "b" passed null to method "a". the rest of article goes more detail , shows mistakes many programmers make can lead nullreferenceexception . more specifically the runtime throwing nullreferenceexception always means same thing: trying use reference, , reference not initialized (or once initialized, no longer initialized). this means reference null , , cannot access members (such methods) through null reference. simplest case: string foo = null; foo.toupper(); this throw nullreferenceexception @ second line because can't call instance method toupper() on string reference pointing null ....
Read more