Wk10: SQL
Defining data
-have a better idea of what kinds of data you want to store and ways of catagorizing it
create categories, use them for data : ex first name, last name
(columns and rows)
database=container that holds info organised into tables
-all tables in databases should be connected somehow
-sql requires all tables to be inside of databases
-good to use descriptive names for databases, tables, columns
-drop table deletes your table and any data in it
-you need to match up column names and values before writing ‘insert’ statement
-NULL is an unidentified value
alright, so I’m starting to feel like I need to be doing the work instead of just reading because I’m not 100% sure I’m following all this info……
***I really need to learn by doing and following along for this kind of stuff….reading it doesn’t cut it for me.***
Chap.2
= is SQL speak for ‘is’
use ‘*’ to select all columns in table
can combine 2 queries with ‘or’ – when you want any of conditions to be true
when you want all conditions to be true use ‘and’
% stand-in for any unknown number of caracters
_ stand-in for one unknown carcter
