WDI Action Adventure

Day9.md

case

like if else without all the if/else

case
  when then 
  when then 
  else
end
end
end

• self = calling on the object

WEB APPS

CRUD Create Read Update Destroy (used with databases)

[2, 11, 37, 42]map! do |n|
n + 5
end

• takes an array ([2, 11, 37, 42])
• .map creates a new array
• updates the new array with (n+5)
• destroys the old array

RESTful Design representational state transfer

GET- Read POST - Create PUT - Replace Update PATCH - Merge Update (only to make one change) DELETE - Destroy

get "/movies"
get "/movies/:id"
post "/movies"
patch "/movies/:id/authors"
put "/movies/:id"
delete "/movies/:id"

• most often used with http but used with JS, js.node, ruby, most platforms
• when POSTing a new hash, the database will create a new id for the new item

*"Who is the fool? The fool who goes or the fool who follows him?" -Obiwan

*BACKEND- store and manipulate data *relationship between browser and web app

Databases

*Types of databases

• json

• realtion

• sql

• xml

• spreadsheet (csv)

• Key/Value

• Brands *Mongo, SQLite, Postgress, Oracle

SQL

• Sturucted Query Language
• relational algebra symbols

*Select, Insert, Update, Delete

• Classes = Tables(CSV)

• Arrays = result set (several rows)

• Hash(instance) = row

• keys(properties/attributes) - column, field names

• values = fields

• schema all tables in a database

• SELECT * FROM displays all the fields from that class

• INSERT INTO "table name" (name the parameters) VALUES (specifics with the parameters)

• WHERE more specific parameters

• LIKE "dav%" will search for anything with those parameters

• can look at all the products or all the users of the products

• Ex. How to look up a specific users wishlist SELECT user_id, product_id FROM wishlists WHERE user_id = 9

• EX. how to look up a specific product SELECT name FROM products WHERE id = 4