Coding against databases - Revision history

WikiSysop: /* Exercises */

2025-09-25T17:10:23Z

Exercises

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 If you look closely at your results, you will find some very interesting family patterns - such is the curse of (badly) generated data.
-'''3) Somewhat optional'''<br>
+'''3) Somewhat optional - really simple once it works'''<br>
 Run your programs again, but this time locally on your laptop, while you use the database on the server.<br>
 This is an interesting challenge, which can be solved by SSH tunneling the mysql port 3306 to the server. The requirements for solving the exercise is understanding and setting up proper SSH tunneling as taught in lesson 1, and that mysql.connector is locally installed in your python distribution.
 In principle, this is done by 1 unix command setting up the SSH tunnel.
-=== Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board ===
+===Chatboard exercise moved to next lesson===

WikiSysop: /* Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board */

2025-09-23T11:45:00Z

Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board

← Older revision		Revision as of 13:45, 23 September 2025
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	This is a fun cooperative exercise with databases. You should all make your own Chat client, where you can communicate with the other course participants. The exercise utilizes the concurrent features of databases - the easy update without worry if somebody else is accessing the database at the same time.		This is a fun cooperative exercise with databases. You should all make your own Chat client, where you can communicate with the other course participants. The exercise utilizes the concurrent features of databases - the easy update without worry if somebody else is accessing the database at the same time.

	You use a database called ''chatboard'' that is common to you all. In that database there will be just one table, ''messages'' with the fields; id (primary key auto_increment), mesg (varchar(500)), name (varchar(15), default NULL), channel (varchar(12), default 'common'), stamp (timestamp). You only have the ability to read the table and insert new rows in the table - that is - create new messages. Only the moderator can delete messages.<br>		You use a database called ''chatboard'' that is common to you all. In that database there will be just one table, ''messages'' with the fields; id (primary key auto_increment), mesg (varchar(500)), name (varchar(15), default NULL), channel (varchar(12), default 'common'), stamp (timestamp) default CURRENT_TIMESTAMP, which means the timestamp is automatically created when the message is inserted. You only have the ability to read the table and insert new rows in the table - that is - create new messages. Only the moderator can delete messages.<br>
	''mesg'' is the message on the chat.<br>		''mesg'' is the message on the chat.<br>
	''name'' is name of the message sender. If NULL, then it is anonymous.<br>		''name'' is name of the message sender. If NULL, then it is anonymous.<br>

WikiSysop: /* Exercises */

2025-09-21T11:40:42Z

Exercises

← Older revision		Revision as of 13:40, 21 September 2025
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	'''1)'''<br>		'''1)'''<br>
	Who are born out of wedlock? Definition: A child is born out of wedlock if the biological father and mother is not married when the child is born. In the absence of information, you can not claim a child is born out of wedlock (that means if you only know the mother from the database, you can not claim the child is a bastard).<br>		Who are born out of wedlock? Definition: A child is born out of wedlock if the biological father and mother is not married when the child is born. In the absence of information, you can not claim a child is born out of wedlock (that means if you only know the mother from the database, you can not claim the child is a bastard).<br>
	According to my results: 262 people are born out of wedlock.		According to my results: 262 people are born out of wedlock. That is amazing as it is out of 500 people.

	'''2)'''<br>		'''2)'''<br>

WikiSysop: /* Exercises */

2025-09-21T11:35:49Z

Exercises

← Older revision		Revision as of 13:35, 21 September 2025
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	'''1)'''<br>		'''1)'''<br>
	Who are born out of wedlock? Definition: A child is born out of wedlock if the biological father and mother is not married when the child is born. In the absence of information, you can not claim a child is born out of wedlock (that means if you only know the mother from the database, you can not claim the child is a bastard).		Who are born out of wedlock? Definition: A child is born out of wedlock if the biological father and mother is not married when the child is born. In the absence of information, you can not claim a child is born out of wedlock (that means if you only know the mother from the database, you can not claim the child is a bastard).<br>
			According to my results: 262 people are born out of wedlock.

	'''2)'''<br>		'''2)'''<br>

WikiSysop: /* Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board */

2025-09-21T09:55:53Z

Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board

← Older revision		Revision as of 11:55, 21 September 2025
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	elif input is command2:		elif input is command2:
	do command2 code		do command2 code
	elif input is ~~nothing:~~		elif input is something:
	~~pass~~
	~~else~~:
	input was a message, so post it to the chat board		input was a message, so post it to the chat board
	pull chat board for new messages and display them if any		pull chat board for new messages and display them if any
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	close database connection		close database connection
	</pre>		</pre>
			As you hopefully can see, this structure makes it easy to start small with simple things and build up with new expanded functionality.

	A command is an input where the first word starts with slash possibly followed by a parameter. Anything else is just a message to be posted on the selected channel.<br>		A command is an input where the first word starts with slash possibly followed by a parameter. Anything else is just a message to be posted on the selected channel.<br>
	<b>List of commands:</b><br>		<b>List of commands:</b><br>
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	/nick <nickname> Sets your name to <nickname>.		/nick <nickname> Sets your name to <nickname>.
	/activity Which channels had the latest messages, and when.		/activity Which channels had the latest messages, and when.
			/last <X> Pull last X messages from the chosen channel and display.
	</pre>		</pre>
	You can implement your own commands, like ''/search <name>'', which would search for messages by the person. ''/who'', which would show who has messages. ''/dance'', which displays a message "<yourname> is dancing for you". You dream it up - it is your chat client and the more powerful and funny it is, the better chances of you being the next Mark Zuckerberg.		You can implement your own commands, like ''/search <name>'', which would search for messages by the person. ''/who'', which would show who has messages. ''/dance'', which displays a message "<yourname> is dancing for you". You dream it up - it is your chat client and the more powerful and funny it is, the better chances of you being the next Mark Zuckerberg.

WikiSysop: /* Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board */

2025-09-21T08:03:04Z

Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board

← Older revision		Revision as of 10:03, 21 September 2025
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	This is a fun cooperative exercise with databases. You should all make your own Chat client, where you can communicate with the other course participants. The exercise utilizes the concurrent features of databases - the easy update without worry if somebody else is accessing the database at the same time.		This is a fun cooperative exercise with databases. You should all make your own Chat client, where you can communicate with the other course participants. The exercise utilizes the concurrent features of databases - the easy update without worry if somebody else is accessing the database at the same time.

	You use a database called ''chatboard'' that is common to you all. In that database there will be just one table, ''messages'' with the fields; id (primary key auto_increment), mesg (varchar(500)), name (varchar(15), default NULL), channel (varchar(12), default 'common'), stamp (timestamp). You only have the ability to insert new rows in the table - that is - create new messages. Only the moderator can delete messages.<br>		You use a database called ''chatboard'' that is common to you all. In that database there will be just one table, ''messages'' with the fields; id (primary key auto_increment), mesg (varchar(500)), name (varchar(15), default NULL), channel (varchar(12), default 'common'), stamp (timestamp). You only have the ability to read the table and insert new rows in the table - that is - create new messages. Only the moderator can delete messages.<br>
	''mesg'' is the message on the chat.<br>		''mesg'' is the message on the chat.<br>
	''name'' is name of the message sender. If NULL, then it is anonymous.<br>		''name'' is name of the message sender. If NULL, then it is anonymous.<br>

WikiSysop: /* Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board */

2025-09-21T07:54:48Z

Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board

← Older revision		Revision as of 09:54, 21 September 2025
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	This is a fun cooperative exercise with databases. You should all make your own Chat client, where you can communicate with the other course participants. The exercise utilizes the concurrent features of databases - the easy update without worry if somebody else is accessing the database at the same time.		This is a fun cooperative exercise with databases. You should all make your own Chat client, where you can communicate with the other course participants. The exercise utilizes the concurrent features of databases - the easy update without worry if somebody else is accessing the database at the same time.

	You use a database called ''chatboard'' that is common to you all. In that database there will be just one table, ''messages'' with the fields; id (primary key auto_increment), mesg (varchar(500)), name (varchar(15), default NULL), channel (varchar(12), default 'common'), stamp (timestamp). You only have the ability to insert new rows in the table - that is - create new messages. Only the moderator can delete messages. ~~'''This database and table is NOT CREATED YET.'''~~<br>		You use a database called ''chatboard'' that is common to you all. In that database there will be just one table, ''messages'' with the fields; id (primary key auto_increment), mesg (varchar(500)), name (varchar(15), default NULL), channel (varchar(12), default 'common'), stamp (timestamp). You only have the ability to insert new rows in the table - that is - create new messages. Only the moderator can delete messages.<br>
	''mesg'' is the message on the chat.<br>		''mesg'' is the message on the chat.<br>
	''name'' is name of the message sender. If NULL, then it is anonymous.<br>		''name'' is name of the message sender. If NULL, then it is anonymous.<br>

WikiSysop: /* Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board */

2025-09-21T06:38:30Z

Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board

← Older revision		Revision as of 08:38, 21 September 2025
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	This is a fun cooperative exercise with databases. You should all make your own Chat client, where you can communicate with the other course participants. The exercise utilizes the concurrent features of databases - the easy update without worry if somebody else is accessing the database at the same time.		This is a fun cooperative exercise with databases. You should all make your own Chat client, where you can communicate with the other course participants. The exercise utilizes the concurrent features of databases - the easy update without worry if somebody else is accessing the database at the same time.

	You use a database called ''chatboard'' that is common to you all. In that database there will be just one table, ''messages'' with the fields; id (primary key ~~autoincrement~~), mesg (varchar(500)), name (varchar(15), default NULL), channel (varchar(12), default 'common'), ~~timestamp~~ (timestamp). You only have the ability to insert new rows in the table - that is - create new messages. Only the moderator can delete messages. '''This database and table is NOT CREATED YET.'''<br>		You use a database called ''chatboard'' that is common to you all. In that database there will be just one table, ''messages'' with the fields; id (primary key auto_increment), mesg (varchar(500)), name (varchar(15), default NULL), channel (varchar(12), default 'common'), stamp (timestamp). You only have the ability to insert new rows in the table - that is - create new messages. Only the moderator can delete messages. '''This database and table is NOT CREATED YET.'''<br>
	''mesg'' is the message on the chat.<br>		''mesg'' is the message on the chat.<br>
	''name'' is name of the message sender. If NULL, then it is anonymous.<br>		''name'' is name of the message sender. If NULL, then it is anonymous.<br>
	''channel'' is the channel for this message. Ask google if you don't know what a chat channel is. If NULL, it is the common channel.<br>		''channel'' is the channel for this message. Ask google if you don't know what a chat channel is. If NULL, it is the common channel.<br>
	''~~timestamp~~'' is when the message is created. This is used for selecting the newest messages and deleting the old.		''stamp'' is when the message is created. This is used for selecting the newest messages and deleting the old.

	The Chat client you make should have the following structure.		The Chat client you make should have the following structure.

WikiSysop: /* Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board */

2025-09-21T06:26:58Z

Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board

← Older revision		Revision as of 08:26, 21 September 2025
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	It could copy other posters - simply repeating their message.<br>		It could copy other posters - simply repeating their message.<br>
	It could advertise an event across all channels.<br>		It could advertise an event across all channels.<br>
	It could have a list of people's birthdays, and when the day came about, post "Today is X's birthday" on the common channel.		It could have a list of people's birthdays, and when the day came about, post "Today is X's birthday" on the common channel.<br>
	If anybody posted a calculation, it could compute the result and post it - just like google.		If anybody posted a calculation, it could compute the result and post it - just like google.

WikiSysop: /* Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board */

2025-09-21T06:26:34Z

Totally optional extra exercise I invented in my dreams Sunday morning: The Chat Board

← Older revision		Revision as of 08:26, 21 September 2025
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	It could advertise an event across all channels.<br>		It could advertise an event across all channels.<br>
	It could have a list of people's birthdays, and when the day came about, post "Today is X's birthday" on the common channel.		It could have a list of people's birthdays, and when the day came about, post "Today is X's birthday" on the common channel.
			If anybody posted a calculation, it could compute the result and post it - just like google.

	I think that was enough ideas for bots.		I think that was enough ideas for bots.

	The fun part of this exercise is you can use the Chat Board for the rest of the course, once you made the client. You can even develop your client and/or bot more in the progress of the course. Once you get the the SSH tunneling set up, you just run your client from home/your laptop. How can it get any better?		The fun part of this exercise is you can use the Chat Board for the rest of the course, once you made the client. You can even develop your client and/or bot more in the progress of the course. Once you get the the SSH tunneling set up, you just run your client from home/your laptop. How can it get any better?