Now that you have a good understanding of the Knex's capabilities, let's look at adding Knex to our Express app endpoints. Quit the nodemon drills.js process and start the server.
Open Postman and navigate to http://localhost:8080/restaurants. You should get back a list of restaurants. The SELECT statement is straight forward, the only thing to point out is the addition of in the `.then(results => res.json(results) );
Let's tackle the grade first.
Migrations are a way to make database changes or updates, like creating or dropping tables, as well as updating a table with new columns with constraints via generated scripts. We can build these scripts via the command line using knex command line tool.
To learn more about migrations, check out this article on the different types of database migrations!
When querying your database in Sequelize, you'll often want data associated with a particular model which isn't in the model's table directly. This data is usually typically associated through join tables (e.g. a 'hasMany' or 'belongsToMany' association), or a foreign key (e.g. a 'hasOne' or 'belongsTo' association).
When you query, you'll receive just the rows you've looked for. With eager loading, you'll also get any associated data. For some reason, I can never remember the proper way to do eager loading when writing my Sequelize queries. I've seen others struggle with the same thing.
Eager loading is confusing because the 'include' that is uses has unfamiliar fields is set in an array rather than just an object.
So let's go through the one query that's worth memorizing to handle your eager loading.
| package main | |
| // http://play.golang.org/p/jZ5pa944O1 <- will not display the colors | |
| import "fmt" | |
| const ( | |
| InfoColor = "\033[1;34m%s\033[0m" | |
| NoticeColor = "\033[1;36m%s\033[0m" | |
| WarningColor = "\033[1;33m%s\033[0m" | |
| ErrorColor = "\033[1;31m%s\033[0m" | |
| DebugColor = "\033[0;36m%s\033[0m" |
