mysql - Designing my first database schema: suggestion needed -

-

this first database schema design. trying develop small web application department used food cost management. , doing learning purpose.

how food cost management works in department:

  1. total members: 15
  2. one admin keep record of cost. update database on daily basis.
  3. each member can order once day. if has guest on specific day can order multiple number of meal.
  4. usually members pay bill week or 2 in advance.
  5. one or 2 persons responsible bringing food outside , don't need pay lunch. transportation cost given them. food cost+ transportation cost distributed equally other 15 members expenses.

database queries:

from admin perspective:

  1. he manage/add daily order. (table: orders)
  2. he add payments members credited against respective member's "balance" (table: payments)
  3. he able see overview of members' order/cost history , current balance in chart 1 month @ time.
  4. if member has negative balance or less specific amount of money, notified admin dashboard.

from member perspective:

  1. he able see current balance , order/cost history last 1 month @ time.
  2. he able see last x number of payment history made.

based on queries mentioned above tried design database schema looks diagram below:

database schema diagram

elaboration of attributes:

eplatenum: number of plate of food brought besides number of plate ordered.

eplatecost: cost plate of food. cost distributed equally among 15members individual cost.

epersonnum & epersoncost: number of person involved in bringing food , total cost. cost distributed equally among 15members individual cost.

transcost: transportation cost. cost distributed equally among 15members individual cost.

questions:

  1. what mistakes have made , how can overcome them?

  2. for dailylist table have used "date" primary key.is ok use date primary key? if not ok, can primary key here instead?

  3. when going populate chart overview 30 months cost/order history database query huge assume. approach should take optimize query?

i looking forward getting suggestions on improving database schema. please me correcting design mistakes , overcome them. thank patience.

my first impression:

  1. i think payment should related order (because user pays specific order).
  2. i don't know dailylist is, if there may more 2 same date (and can image may be) shouldn't use primari key.
  3. password should encoded e.g. sha (so varchar 15 less).

Comments

Post a Comment

Popular posts from this blog

Perl - how to grep a block of text from a file -

-
it can in xml or text format. how in general grep block of text in perl? <track type="ws"> <range> <rangestart>0</rangestart> <rangeend>146.912</rangeend> <locationindex>0</locationindex> <propertyindex>0</propertyindex> </range> </track> <track type="ps" id="1"> <range> <rangestart>0</rangestart> <rangeend>146.912</rangeend> <locationindex>1</locationindex> <propertyindex>1</propertyindex> </range> </track> i want grep type="ps" , till </range> . one solution open file, read line line , match block. open(fh, "file.txt"); foreach $line (<fh>) { if ($line =~ m/type="cc"(.*?)<\/range>/) { print $1; } } but there more optimal solution without reading file line l
Read more

delphi - How to remove all the grips on a coolbar if I have several coolbands? -

-
Image
if set mycoolbar.fixedorder true,only grip on first band hidden. well,if use delphi 7 create vcl forms application,then put coolbar on , create 3 coolbans hold other controls,only grip , top coolbands can hidden setting mycoolbar.fixedorder:=true. i've uploaded picture make things clear. you got fixedorder property wrong. fixed property not allow bands rearranged if set true . setting property of coolbar true keep user changing bands order @ runtime, user can still move , resize bands. can give advice can do, actual solution problem, well, have wait answer. my advice use 3 coolbars in row , setting "fixedorder" property true , bandborderstyle bsnone . way grip hidden on of them. about property, it's not bug of ide, actual preference of property.
Read more

javascript - Animating array of divs; only the final element is modified -

-
this baffling me @ moment. i'm experienced programmer looking throw bit of surprise fiancee on countdown page our wedding. desired effect simulated confetti falling behind main page. setup follows: i have array of divs in javascript. each div absolutely positioned on page. have interval set updates every 50 or milliseconds. on each tick, run loop on array of divs, , calculations , update positions. problem problem having, however, though can see divs created, stored array, , modified (in case, each has slight randomized rotation) during initialization phase, once tick update position starts, div stored in whatever last slot of array gets position updated. tried hard-coding each div index testing purposes, strictly last element update position. upon printing current "left" , "top" style values each div before , after calculations shows value has been changed, no visible change noticeable. here's basic code: javascript var container;
Read more