devleague / select-todo-from-list

SQL CRUD Exercise in PostgreSQL

SELECT todo FROM list

SQL CRUD Exercise in PostgreSQL

Prepare SQL statements while testing them on a local running database.

Docker Setup

Set your database name to be tasks.
Set your database username to be tasker.
Set your database password to be taskMaster.

To Do List Application

Write these SQL statements in todo_app.sql, and run them against your newly created database:

1. Write a query to drop the table tasks if it exists.
2. Write a query to create a table named tasks using the Initial columns detailed below
3. Define column id as the table's primary key
4. Write queries to accomplish the following
5. remove the column named completed
6. add a column to tasks named completed_at:timestamp, that may be NULL, and has a default value of NULL.
7. change the updated_at column to not allow NULL values, and have a default value of now()
8. create a new task, by only setting values (not defining which columns) id = default value
title = 'Study SQL'
description = 'Complete this exercise'
created_at = now()
updated_at = now()
completed_at = NULL
9. create a new task
   title = 'Study PostgreSQL'
description = 'Read all the documentation'
10. select all the titles of tasks that are not yet completed
11. update the task with a title of 'Study SQL' to be completed as of now
12. select all titles and descriptions of tasks that are not yet completed
13. select all fields of every task sorted by creation date in descending order
14. create a new task
    title = 'mistake 1'
description = 'a test entry'
15. create a new task
    title = 'mistake 2'
description = 'another test entry'
16. create a new task
    title = 'third mistake'
description = 'another test entry'
17. select title fields of all tasks with a title that includes the word 'mistake'
18. delete the task that has a title of mistake 1
19. select title and description fields of all tasks with a title that includes the word 'mistake'
20. delete all tasks that includes the word 'mistake' in the title
21. select all fields of all tasks sorted by title in ascending order

Initial Columns for tasks

Column Name	Datatype	NULL	Default
id	integer	false	auto incrementing
title	character varying (255)	false
description	text	true
created_at	timestamp (no tz)	false	now()
updated_at	timestamp (no tz)	true
completed	boolean	false	false

Final Columns for tasks

Column Name	Datatype	NULL	Default
id	integer	false	auto incrementing
title	character varying (255)	false
description	text	true
created_at	timestamp (no tz)	false	now()
updated_at	timestamp (no tz)	false	now()
completed_at	timestamp (no tz)	true	NULL

select-todo-from-list's Issues

Drop db before dropping user

Put drop DB step before dropping user step because running subsequent student scripts will say that user cant be dropped because objects depend on it.

Drop table on todo_app.sql

Start that todo_app.sql file with a drop table if exists so that re-running the file is much easier.