kroneman/sql-learning

A convenient way to learn SQL

SQL Course Playground

Setup

1. Install docker ce if you haven't already.
2. Open a terminal and navigate to the root of this project
3. Start mysql server

docker-compose up

4. Use the name a query with the bin/sqlrun command to execute queries against the running database

e.g.

bin/sqlrun ./sequence.txt

Running bin/sqlrun without arguments will run all queries in the ./queries folder

Running bin/sqlrun ./sequence.txt will run queries in the order specified in the file

Course Cliff-Notes

1. Name of a table is what each row is about
2. Good practice to prefix column names with the table name
3. Using * is bad practice, better to be explicit
4. Good practice to qualify select with table name.

SELECT person.person_id, person.person_firstname, person.person_lastname FROM person

5. Best practice to qualify and to alias

SELECT
    p.person_id,
    p.person_firstname,
    p.person_lastname
FROM person p