Wladimir Fraga CS10

queries.sql

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+# Wladimir Fraga CS10
+
+-- Create tables
+CREATE TABLE organization (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  name VARCHAR (64) NOT NULL UNIQUE,
+  created TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE TABLE channel (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  name VARCHAR (64) NOT NULL UNIQUE,
+  organization_id INTEGER REFERENCES organization(id),
+  created TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+  updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE TABLE user (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  name VARCHAR (64) NOT NULL,
+  username VARCHAR (32) NOT NULL UNIQUE,
+  created TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+  updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE TABLE message (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  content TEXT,
+  user_id INTEGER REFERENCES user(id),
+  channel_id INTEGER REFERENCES channel(id),
+  created TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+  updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+-- Join tables
+CREATE TABLE user_channel
+(
+  user_id INTEGER REFERENCES user(id),
+  channel_id INTEGER REFERENCES channel(id)
+);
+
+
+--Insert data into databse
+INSERT INTO organization (name) VALUES("Lambda School");
+
+INSERT INTO user (name, username) VALUES("Alice", "littlegirl");
+
+INSERT INTO user (name, username) VALUES("Bob", "theboss");
+
+INSERT INTO user (name, username) VALUES("Chris", "coolguy");
+
+INSERT INTO channel (name, organization_id) VALUES("#general", 1);
+
+INSERT INTO channel (name, organization_id) values("#random", 1);
+
+--Insert 10 messages 
+INSERT INTO message (content, user_id, channel_id) VALUES("Is this the lambda general channel?", 1, 1);
+INSERT INTO message (content, user_id, channel_id) VALUES("Yes you are in the lambda general channel, the coolest channel", 3, 1);
+INSERT INTO message (content, user_id, channel_id) VALUES("Welcome to the lambda general channel littlegirl, I'm Bob theboss", 2, 1);
+INSERT INTO message (content, user_id, channel_id) VALUES("Thank You guys, I'm new here there is another channel were i can post any subject", 1, 1);
+
+INSERT INTO message (content, user_id, channel_id) VALUES("Breakout written in, uh, PDF.", 2, 2);
+
+INSERT INTO message (content, user_id, channel_id) VALUES("Try the #random channel", 2, 1);
+INSERT INTO message (content, user_id, channel_id) VALUES("I'm getting ready to jump into lambda labs next week", 3, 1);
+
+INSERT INTO message (content, user_id, channel_id) VALUES("No way, Beej maybe did it, madman lol", 3, 2);
+
+INSERT INTO message (content, user_id, channel_id) VALUES("What is lamdba labs?", 1, 1);
+INSERT INTO message (content, user_id, channel_id) VALUES("Where the cool guys code real life apps", 3, 1);
+
+INSERT INTO user_channel (user_id, channel_id) VALUES(1,1);
+INSERT INTO user_channel (user_id, channel_id) VALUES(1,2);
+
+INSERT INTO user_channel (user_id, channel_id) VALUES(2,1);
+
+INSERT INTO user_channel (user_id, channel_id) VALUES(3,2);
+
+--select data
+
+
+SELECT name FROM organization;
+
+SELECT name FROM channel;
+
+SELECT channel.name FROM channel, organization WHERE organization_id = organization.id AND organization.name= "Lambda School";
+
+SELECT content FROM message, channel WHERE channel_id = channel.id AND channel.name = "#general" ORDER BY message.created DESC;
+
+SELECT channel.name FROM user, channel, user_channel WHERE user.id = user_id AND channel.id = channel_id AND user.name  = "Alice";
+
+SELECT user.name FROM user, channel, user_channel WHERE user.id = user_id AND channel.id = channel_id AND channel.name  = "#general";
+
+SELECT content FROM message, user WHERE user_id = user.id AND user.name = "Alice";
+
+SELECT message.content AS "Message" FROM user, channel, message WHERE user.id=message.user_id AND channel.id=message.channel_id AND channel.name="#random" AND user.name="Bob";
+
+.mode column
+.header on
+SELECT user.name AS "User Name", COUNT(message.content) AS "Message Count" FROM user, message WHERE user.id=message.user_id GROUP BY "User Name";
+
+
+-- Question: What SQL keywords or concept would you use if you wanted to automatically delete all messages by a user if that user were deleted from the user table?
+
+-- Answer: "ON DELTE CASCADE" 
+
+SELECT user.name AS User, channel.name AS Channel, COUNT(message.content) AS "Message Count" FROM user, channel, message WHERE user.id=message.user_id AND channel.id=message.channel_id GROUP BY User, Channel ORDER BY User;

todo.md

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+# Sprint Challenge: SQL
+
+Design a database for an online chat system.
+
+## Deliverables
+
+* [ ] Add a file called `queries.sql` that runs all of the `CREATE TABLE`,
+`INSERT`, and `SELECT` queries, below.
+
+The last question is a fill-in-the-blank. You can add that as a SQL
+comment to the end of `queries.sql`.
+
+## Details
+
+1. Write `CREATE TABLE` statements for tables `organization`, `channel`, `user`,
+   and `message`.
+
+   1. * [ ] `organization`. This table should at least have column(s):
+      * `name`
+
+   2. * [ ] `channel`. This table should at least have column(s):
+      * `name`
+
+   3. * [ ] `user`. This table should at least have column(s):
+      * `name`
+
+   4. * [ ] `message`. This table should have at least columns(s):
+
+      * `post_time`--the timestamp of when the message was posted
+        * See [Date types in
+          SQLite](https://www.sqlite.org/datatype3.html#date_and_time_datatype).
+          Also see the SQLite function `datetime()`.
+
+      * `content`--the message content itself
+
+2. * [ ] Add additional foreign keys needed to the above tables, if any.
+
+3. * [ ] Add additional join tables needed, if any.
+
+4. Write `INSERT` queries to add information to the database.
+
+   For these `INSERT`s, it is OK to refer to users, channels, and organization
+   by their `id`s. No need to do a subselect unless you want to.
+
+   1. * [ ] One organization, `Lambda School`
+   2. * [ ] Three users, `Alice`, `Bob`, and `Chris`
+   3. * [ ] Two channels, `#general` and `#random`
+   4. * [ ] 10 messages (at least one per user, and at least one per channel).
+   5. * [ ] `Alice` should be in `#general` and `#random`.
+   6. * [ ] `Bob` should be in `#general`.
+   7. * [ ] `Chris` should be in `#random`.
+
+5. Write `SELECT` queries to:
+
+   For these `SELECT`s, it is **NOT** OK to refer to users, channels, and
+   organization by their `id`s. You must join in those cases.
+
+   1. * [ ] List all organization `name`s.
+
+   2. * [ ] List all channel `name`s.
+
+   3. * [ ] List all channels in a specific organization by organization `name`.
+
+   4. * [ ] List all messages in a specific channel by channel `name` `#general` in
+      order of `post_time`, descending. (Hint: `ORDER BY`. Because your
+      `INSERT`s might have all taken place at the exact same time, this might
+      not return meaningful results. But humor us with the `ORDER BY` anyway.)
+
+   5. * [ ] List all channels to which user `Alice` belongs.
+
+   6. * [ ] List all users that belong to channel `#general`.
+
+   7. * [ ] List all messages in all channels by user `Alice`.
+
+   8. * [ ] List all messages in `#random` by user `Bob`.
+
+   9. * [ ] List the count of messages across all channels per user. (Hint:
+      `COUNT`, `GROUP BY`.)
+
+      The title of the user's name column should be `User Name` and the title of
+      the count column should be `Message Count`. (The SQLite commands
+	  `.mode column` and `.header on` might be useful here.)
+
+      The user names should be listed in reverse alphabetical order.
+
+      Example:
+
+      ```
+      User Name   Message Count
+      ----------  -------------
+      Chris       4
+      Bob         3
+      Alice       3
+      ```
+
+   10. * [ ] [Stretch!] List the count of messages per user per channel.
+
+       Example:
+
+       ```
+       User        Channel     Message Count
+       ----------  ----------  -------------
+       Alice       #general    1
+       Bob         #general    1
+       Chris       #general    2
+       Alice       #random     2
+       Bob         #random     2
+       Chris       #random     2
+       ```
+
+6. * [ ] What SQL keywords or concept would you use if you wanted to automatically
+   delete all messages by a user if that user were deleted from the `user`
+   table?