Cass Lamendola

README.md

@@ -36,26 +36,40 @@ various tables, not just the columns listed here.
 
    1. `organization`. This table should at least have column(s):
       * `name`
+      * `id`
 
    2. `channel`. This table should at least have column(s):
       * `name`
+      * `id`
 
    3. `user`. This table should at least have column(s):
       * `name`
+      * `id`
 
    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
+      * `id`
 
 2. Add additional foreign keys needed to the above tables, if any.
 
+   1. `channel`. This table should also have column(s):
+      * `organization_id`
+
+   2. `message`. This table should have also columns(s):
+      * `user_id`
+      * `channel_id`
+
 3. Add additional join tables needed, if any.
 
+   1. subscriptions
+      * `user_id`
+      * `channel_id`
+
+
 4. Write `INSERT` queries to add information to the database.
 
    For these `INSERT`s, it is OK to refer to users, channels, and organization
@@ -130,3 +144,5 @@ various tables, not just the columns listed here.
 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?
+
+    CASCADE DELETE

queries.sql

@@ -0,0 +1,122 @@
+-- CREATE TABLES
+CREATE TABLE organization {
+  id int AUTOINCREMENT,
+  organization_name varchar(255) NOT NULL,
+  PRIMARY KEY (id)
+};
+
+CREATE TABLE channel {
+  id int AUTOINCREMENT,
+  channel_name varchar(255) NOT NULL,
+  organization_id int NOT NULL,
+  PRIMARY KEY (id),
+  FOREIGN KEY (organization_id) REFERENCES organization(id)
+};
+
+CREATE TABLE user {
+  id int AUTOINCREMENT,
+  person_name varchar(255) NOT NULL,
+  PRIMARY KEY (id),
+};
+
+CREATE TABLE message {
+  id int AUTOINCREMENT,
+  content varchar(255) NOT NULL,
+  channel_id int NOT NULL,
+  post_time default current_timestamp
+  user_id int NOT NULL,
+  PRIMARY KEY (id),
+  FOREIGN KEY (channel_id) REFERENCES channel(id)
+  FOREIGN KEY (user_id) REFERENCES user(id)
+};
+
+CREATE TABLE subscriptions {
+  id int AUTOINCREMENT,
+  channel_id int NOT NULL,
+  user_id int NOT NULL,
+  PRIMARY KEY (id),
+  FOREIGN KEY (channel_id) REFERENCES channel(id)
+  FOREIGN KEY (user_id) REFERENCES user(id)
+};
+
+-- INSERT DATA
+INSERT INTO organization
+VALUES ('Lambda School');
+
+INSERT INTO user
+VALUES ('Alice');
+
+INSERT INTO user
+VALUES ('Bob');
+
+INSERT INTO user
+VALUES ('Chris');
+
+INSERT INTO channel
+VALUES ('#general', 1);
+
+INSERT INTO channel
+VALUES ('#random', 1);
+
+INSERT INTO subscriptions
+VALUES (1, 1);
+
+INSERT INTO subscriptions
+VALUES (2, 1);
+
+INSERT INTO subscriptions
+VALUES (1, 2);
+
+INSERT INTO subscriptions
+VALUES (2, 3);
+
+-- SELECT QUERIES
+
+-- 1
+SELECT organization_name FROM organization;
+
+-- 2
+SELECT channel_name FROM channel;
+
+-- 3
+SELECT channel_name FROM channel, organization 
+WHERE organization_id = organization.id
+AND organization_name = 'Lambda School';
+
+-- 4
+SELECT content FROM channel, message
+WHERE channel_id = message.channel_id
+AND channel_name = '#general'
+ORDER BY post_time;
+
+-- 5
+SELECT channel_name FROM user, channel, subscriptions
+WHERE subscriptions.user_id = user.id
+AND subscriptions.channel_id = channel.id
+AND person_name = 'Alice';
+
+-- 6
+SELECT person_name from user, channel, subscriptions
+WHERE subscriptions.user_id = user.id
+AND subscriptions.channel_id = channel.id
+AND channel_name = '#general';
+
+-- 7
+SELECT content FROM message, user
+WHERE message.user_id = user.id
+AND user.person_name = 'Alice';
+
+-- 8
+SELECT content FROM message, user, channel
+WHERE channel_id = message.channel_id
+AND message.user_id = user.id
+AND channel_name = '#random'
+AND person_name = 'Bob';
+
+-- 9
+.mode column
+.headers on
+SELECT user.person_name AS 'User Name', COUNT(message.id) as 'Message Count'
+FROM message, user
+WHERE message.user_id = user.id
+GROUP BY user.person_name;