Edward Gonzalez

README.md

@@ -130,3 +130,5 @@ 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?
+
+# Initial Commit

queries.sql

@@ -0,0 +1,140 @@
+-- 1. Write CREATE TABLE statements for tables organization, channel, user, and message.
+    -- i. organization. This table should at least have column(s): 
+    -- name 
+
+CREATE TABLE organization (id INTEGER PRIMARY KEY AUTOINCREMENT, name VARCHAR(100) NOT NULL UNIQUE, created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP, last_modified TIMESTAMP DEFAULT CURRENT_TIMESTAMP); 
+
+CREATE TRIGGER UPDATE_TIMESTAMP_TRIGGER_FOR_ORGANIZATION 
+AFTER UPDATE ON organization
+BEGIN
+    UPDATE organization SET TIMESTAMP = STRFTIME('%Y-%m-%d %H:%M:%f', 'NOW') WHERE id = NEW.id;
+END;
+
+    -- i. channel. This table should at least have column(s): 
+    -- name 
+
+CREATE TABLE channel (id INTEGER PRIMARY KEY AUTOINCREMENT, name VARCHAR(100) NOT NULL UNIQUE, organization_id INTEGER NOT NULL REFERENCES organization(id) ON DELETE CASCADE, created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP, last_modified TIMESTAMP CURRENT_TIMESTAMP); 
+
+CREATE TRIGGER UPDATE_TIMESTAMP_TRIGGER_FOR_CHANNEL  
+AFTER UPDATE ON channel
+BEGIN
+    UPDATE channel SET TIMESTAMP = STRFTIME('%Y-%m-%d %H:%M:%f', 'NOW') WHERE id = NEW.id;
+END;
+
+    -- user. This table should at least have column(s): 
+    -- name    
+
+CREATE TABLE user (id INTEGER PRIMARY KEY AUTOINCREMENT, first_name VARCHAR(100) NOT NULL, last_name VARCHAR(100) NOT NULL, username VARCHAR(50) NOT NULL UNIQUE, created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP, last_modified TIMESTAMP DEFAULT CURRENT_TIMESTAMP); 
+
+CREATE TRIGGER UPDATE_TIMESTAMP_TRIGGER_FOR_USER
+AFTER UPDATE ON user 
+BEGIN
+    UPDATE user SET TIMESTAMP = STRFTIME('%Y-%m-%d %H:%M:%f', 'NOW') WHERE id = NEW.id;
+END;
+
+    -- message. This table should have at least columns(s):
+    -- post_time--the timestamp of when the message was posted
+    -- content--the message content itself
+
+CREATE TABLE message (id INTEGER PRIMARY KEY AUTOINCREMENT, content TEXT, user_id INTEGER REFERENCES user(id) ON DELETE CASCADE, channel_id INTEGER REFERENCES channel(id) ON DELETE CASCADE, post_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP, last_modified TIMESTAMP DEFAULT CURRENT_TIMESTAMP); 
+
+CREATE TRIGGER UPDATE_TIMESTAMP_TRIGGER_FOR_MESSAGE
+AFTER UPDATE ON message
+BEGIN
+    UPDATE message SET TIMESTAMP = STRFTIME('%Y-%m-%d %H:%M:%f', 'NOW') WHERE id = NEW.id;
+END;
+
+-- 2. Add additional foreign keys needed to the above tables, if any.
+-- 3. Add additional join tables needed, if any.
+
+CREATE TABLE user_channel (user_id INTEGER REFERENCES user(id) ON DELETE CASCADE, channel_id INTEGER REFERENCES channel(id) ON DELETE CASCADE); 
+
+-- 4. Write INSERT queries to add information to the database.
+
+    -- One organization, Lambda School
+
+INSERT INTO organization (name) VALUES ('Lambda School'); 
+
+    -- Three users, Alice, Bob, and Chris
+
+INSERT INTO user (first_name, last_name, username) VALUES ('Alice', 'Wonderland', 'alice20');
+INSERT INTO user (first_name, last_name, username) VALUES ('Bob', 'Dillan', 'bobby76');
+INSERT INTO user (first_name, last_name, username) VALUES ('Chris', 'Hay', 'chrisp9');
+
+    -- Two channels, #general and #random
+
+INSERT INTO channel (name, organization_id) VALUES ('#general', 1);
+INSERT INTO channel (name, organization_id) VALUES ('#random', 1);
+
+    -- 10 messages (at least one per user, and at least one per channel).
+
+INSERT INTO message (content, user_id, channel_id) VALUES("I'M THE KING OF THE WORLD", 1, 1);
+INSERT INTO message (content, user_id, channel_id) VALUES("OH, you did an actual query.  That’s awesome lol", 1, 2);
+INSERT INTO message (content, user_id, channel_id) VALUES("Cats are cool.", 2, 1);
+INSERT INTO message (content, user_id, channel_id) VALUES("So many repos.", 3, 2);
+INSERT INTO message (content, user_id, channel_id) VALUES("Don't worry guys.", 3, 2);
+INSERT INTO message (content, user_id, channel_id) VALUES("Why do I type so slow?", 1, 1);
+INSERT INTO message (content, user_id, channel_id) VALUES("Two hours of sleep is rough.", 1, 1);
+INSERT INTO message (content, user_id, channel_id) VALUES("What's the repo for today?", 2, 1);
+INSERT INTO message (content, user_id, channel_id) VALUES("Can you make a PR request please", 2, 1);
+INSERT INTO message (content, user_id, channel_id) VALUES("Do you think I will graduate?", 1, 2);
+
+    -- Alice should be in #general and #random.
+    -- Bob should be in #general.
+    -- Chris should be in #random.
+
+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); 
+
+-- 5. Write SELECT queries to:
+
+    -- List all organization names.
+
+SELECT name FROM organization; 
+
+    -- List all channel names.
+
+SELECT name FROM channel; 
+
+    -- List all channels in a specific organization by organization name.
+
+SELECT channel.name AS 'Channels in Lambda School' FROM channel, organization WHERE channel.organization_id = organization.id AND organization.name = 'Lambda School'; 
+
+    -- List all messages in a specific channel by channel name #general in order of post_time, descending. 
+
+SELECT message.content 'Messages in #general channel ordered by post time in descending order.' FROM message, channel WHERE message.channel_id = channel.id AND channel.name = '#general' ORDER BY message.post_time DESC; 
+
+    -- List all channels to which user Alice belongs.
+
+SELECT channel.name AS 'Channels that Alice belongs to' FROM user, channel, user_channel WHERE user.id = user_channel.user_id AND channel.id = user_channel.channel_id AND user.first_name = 'Alice'; 
+
+    -- List all users that belong to channel #general.
+
+SELECT user.first_name AS 'Users that belong to channel #general' FROM user, channel, user_channel WHERE user.id = user_channel.user_id AND channel.id = user_channel.channel_id AND channel.name = '#general'; 
+
+    -- List all messages in all channels by user Alice.
+
+SELECT message.content AS 'All messages in all channels by user Alice' FROM user, message WHERE user.id = message.user_id AND user.first_name = 'Alice'; 
+
+    -- List all messages in #random by user Bob.
+
+SELECT message.content AS 'All messages in #random by user Bob' FROM user, message, channel WHERE user.id = message.user_id AND message.channel_id = channel.id AND user.first_name = 'Bob' AND channel.name = '#random'; 
+
+    -- List the count of messages across all channels per user.
+
+SELECT user.first_name AS 'User Name', COUNT(message.id) AS 'Message Count' FROM user, message WHERE user.id = message.user_id GROUP BY user.first_name; 
+
+    -- [Stretch!] List the count of messages per user per channel.
+
+SELECT user.first_name AS 'User', channel.name AS 'Channel', COUNT(*) AS 'Message Count' FROM user, channel, message WHERE user.id = message.user_id AND message.channel_id = channel.id GROUP BY channel.name, user.first_name; 
+
+
+-- 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?
+
+PRAGMA FOREIGN_KEYS = ON; 
+
+    -- Use must use "ON DELETE CASCADE" when referencing foreign keys in order to delete all messages by a user if that user were deleted from the user table. 
+
+DELETE FROM user WHERE username = 'alice20';