RelationalDatabase.txt

Aggregations:

a database operation that summarize multiple rows into a single row. (new table)
  Ex: 
  How many rows? count aggregation
  Whats the average? avg aggregation
  Whats the greatest? max aggregation
  Whats the least? min aggregation
  Whats the sum? sum aggregation
  
  https://www.youtube.com/watch?v=ZFn9xVQ0hD4
  
  
  select food from diet where species = 'orangutan'
  
  select = Wer're fetching data out of the database rather than inserting
  food = a column
  from = what table we are talking about (diet)
  where species = 'orangutan' = This is a restriction, it says what rows we want. We want the rows where species = orangutan
  
  We fetch data from a database by writing a code that sends a query to the database and the database responds with sending a new table to us!
  
  
  https://www.youtube.com/watch?v=lXoiI0gx3MU
  https://www.youtube.com/watch?v=PXNaLWJ5SKg
  
  SQL Types:
    text - Same as Str in Python (values are written in 'single quotes')
    integer - Same as Int in Python (but with different limits)
    date - A calendar date. Values are written like this: '2014-04-13' (remember the single quotes so it gets threated as a string)