SQL Crowdfunding Lab
Learning Goals
Identify table example
Create a new table, records, and queries
Identify Table Example
SQL
is a programming language that allows you to "nest" statements inside each other. Let's quickly consider an example using grocery data.
Create a Grocery Table
Selecting Data from the Grocery Table
Given the example SQL above, we'd be able to run a query like
And get back the inserted data (represented in a table below)
SUM
SUM
SUM
will return the total of the column you select. In this case, the total number of items in the groceries
column is 12.
Returns
To make it a little more useful we can GROUP BY
the aisle that the items are in and ORDER BY
the sum of the aisle
.
Returns
Instructions
In this lab, you have two tasks - first, you will need to create three tables in lib/create.sql
, and populate them with data in lib/insert.sql
. Then, you will need to write the necessary SQL statements inside the methods in lib/sql_queries.rb
that would allow you to query data from your newly created tables.
Create New Table, Records and Queries
Now we're going to create a schema based on the following information:
A project has a title, a category, a funding goal, a start date, and an end date.
A user has a name and an age
A pledge has an amount. It belongs to a user, and it also belongs to a project.
Create the Tables
In the create.sql
file, model your tables. You should have a table for projects, users, and pledges.
Insert Records into Database
Within the insert.sql
file, insert 10 projects, 20 users, and 30 pledges into the database.
Write the Queries
Write SQL queries as strings in lib/sql_queries
in each of the provided methods.
Run learn
as you go and read the test messages for additional guidance.
Resources
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