WebFund 2014W Lecture 7 - Revision history

Leah at 17:14, 13 March 2014

2014-03-13T17:14:05Z

← Older revision		Revision as of 17:14, 13 March 2014
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	* rows (records)		* rows (records)
	* columns (fields)		* columns (fields)

			With a relational database, you can quickly compare information because of the arrangement of data in columns. The relational database can build completely new tables out of required information from existing tables. In other words, it uses the relationship of similar data to increase the speed and versatility of the database.

			By storing this information in another table, the database can create a single small table with the locations that can then be used for a variety of purposes by other tables in the database. A typical large database will contain hundreds or thousands of tables like this all used together to quickly find the exact information needed.

	== Example ==		== Example ==

Leah at 17:09, 13 March 2014

2014-03-13T17:09:59Z

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	* Simplest: sorts specific fields in a table (create secondary keys)		* Simplest: sorts specific fields in a table (create secondary keys)

	Secondary key Primary key		{\| class="wikitable"
	~~======== =======~~		\|-
	First Name ID		! Secondary key
	~~--------- -~~-		! Primary key
	Anil 1		\|-
	Dana 2		\| First Name
	Annie 3		\| ID
			\|-
			\| Anil
			\| 1
			\|-
			\| Dana
			\| 2
			\|-
			\| Annie
			\| 3
			\|}

	* sort the names Alphabetically.		* We want to sort the names Alphabetically using the secondary key.

	Transactions:		Transactions:

Leah at 17:07, 13 March 2014

2014-03-13T17:07:32Z

← Older revision		Revision as of 17:07, 13 March 2014
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	Table: Invoices		Table: Invoices

	Inv. ID Description Amount Customer		{\| class="wikitable"
	1 iPad $700 1 <- Which is Anil in the People table)		\|-
	2		! Inv. ID
			! Description
			! Amount
			! Customer
			\|-
			\| 1
			\| iPad
			\| $700
			\| 1 <- Which is Anil in the People table)
			\|-
			\| 2
			\| MacBookPro
			\| $1500
			\| 2 <- Which is Dana in the People table)
			\|}

	* One relation: Invoice = Customer ID -> People ID		* One relation: Invoice = Customer ID -> People ID

Leah at 17:04, 13 March 2014

2014-03-13T17:04:53Z

← Older revision		Revision as of 17:04, 13 March 2014
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	== Example ==		== Example ==

			Table: People
	{\| class="wikitable"		{\| class="wikitable"
	\|-		\|-
	! ~~Header 1~~		! ID
	! ~~Header 2~~		! First Name
	! ~~Header 3~~		! Last Name
			! Phone
			! Email
	\|-		\|-
	\| ~~row 1, cell~~ 1		\| 1
	\| ~~row 1, cell 2~~		\| Anil
	\| ~~row 1, cell 3~~		\| Somayaji
			\| 555-1212
			\| soma@scs.carleton.ca
	\|-		\|-
	\| ~~row~~ 2~~, cell 1~~		\| 2
	\| ~~row 2, cell 2~~		\| Dana
	\| ~~row 2, cell 3~~		\| Somayaji
			\| 555-1212
			\| dana@example.ca (should check whether it is a valid address)
	\|}		\|}

	~~Table: People~~

	~~ID First Name Last Name Phone Email~~
	~~1 Anil Somayaji 555-1212 soma@scs.carleton.ca~~
	~~2 Dana Somayaji 555-1212 dana@example.ca (should check whether it is a valid address)~~

	Validation Problem:		Validation Problem:

Leah at 17:02, 13 March 2014

2014-03-13T17:02:00Z

← Older revision		Revision as of 17:02, 13 March 2014
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	== Example ==		== Example ==

			{\| class="wikitable"
			\|-
			! Header 1
			! Header 2
			! Header 3
			\|-
			\| row 1, cell 1
			\| row 1, cell 2
			\| row 1, cell 3
			\|-
			\| row 2, cell 1
			\| row 2, cell 2
			\| row 2, cell 3
			\|}

	Table: People		Table: People

Leah at 16:59, 13 March 2014

2014-03-13T16:59:41Z

← Older revision		Revision as of 16:59, 13 March 2014
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	* [http://dl.cuol.ca/capture/Anil.Somayaji/COMP_2406_2014W_Lecture_7_-_20140129_143752_27.mp4 Original from CUOL]		* [http://dl.cuol.ca/capture/Anil.Somayaji/COMP_2406_2014W_Lecture_7_-_20140129_143752_27.mp4 Original from CUOL]

	Databases:		== Databases ==
	why?		why?
	* Persistence - You want to stick around (vs. RAM)		* Persistence - You want to stick around (vs. RAM)
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	* columns (fields)		* columns (fields)

	~~Example~~		== Example ==
	=====

	Table: People		Table: People
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	* Simplest: sorts specific fields in a table (create secondary keys)		* Simplest: sorts specific fields in a table (create secondary keys)

	Secondary key Primary key		Secondary key Primary key
	======== =======		======== =======
	First Name ID		First Name ID
	--------- --		--------- --
	>> Anil 1		Anil 1
	~~sort~~ Dana 2		Dana 2
	~~these~~ Annie 3		Annie 3
	~~alphabetically~~
			* sort the names Alphabetically.

	Transactions:		Transactions:

Leah at 16:55, 13 March 2014

2014-03-13T16:55:55Z

← Older revision		Revision as of 16:55, 13 March 2014
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	* [http://www.screencast.com/t/x2iAx5KDyj Large from screencast.com]		* [http://www.screencast.com/t/x2iAx5KDyj Large from screencast.com]
	* [http://dl.cuol.ca/capture/Anil.Somayaji/COMP_2406_2014W_Lecture_7_-_20140129_143752_27.mp4 Original from CUOL]		* [http://dl.cuol.ca/capture/Anil.Somayaji/COMP_2406_2014W_Lecture_7_-_20140129_143752_27.mp4 Original from CUOL]

			Databases:
			why?
			* Persistence - You want to stick around (vs. RAM)
			* Concurrency in writes - (vs. files)
			* Search - (vs. files)
			** Dynamic data should NOT be stored in files.

			SQL(Structured Query Language) vs. NoSQL
			* SQL makes queries to databases, assuming queries are highly structured.
			* for relational databases.

			What is a structure of a relational database?
			e.g. Tables - relations connect fields between tables
			* rows (records)
			* columns (fields)

			Example
			=====

			Table: People

			ID First Name Last Name Phone Email
			1 Anil Somayaji 555-1212 soma@scs.carleton.ca
			2 Dana Somayaji 555-1212 dana@example.ca (should check whether it is a valid address)

			Validation Problem:
			* Where to check for bad data?
			* Can do on:
			** Web client (helpful)
			** Web server (must)
			** Database (useful)

			Example continued:

			Table: Invoices

			Inv. ID Description Amount Customer
			1 iPad $700 1 <- Which is Anil in the People table)
			2

			* One relation: Invoice = Customer ID -> People ID

			Could ask for simple queries:
			* All records in People with first name == Anil
			* Which customer has spent the most in our store?
			** Sum of all invoices for each customer
			** find max

			Indexing:
			* Simplest: sorts specific fields in a table (create secondary keys)

			Secondary key Primary key
			======== =======
			First Name ID
			--------- --
			>> Anil 1
			sort Dana 2
			these Annie 3
			alphabetically

			Transactions:
			* What if I want to change records in multiple tables in a coordinated fashion?
			* Airline example
			** Reserve seat
			** Pay
			** Commit: check that payment and reservation both worked first

			NoSQL Databases: No transactions, no real relations

Soma: Created page with "The video from the lecture given on January 29, 2014 is available: * [http://www.screencast.com/t/5lpc5qWqGBU2 Small from screencast.com] * [http://www.screencast.com/t/x2iAx5..."

2014-01-29T21:49:41Z

Created page with "The video from the lecture given on January 29, 2014 is available: * [http://www.screencast.com/t/5lpc5qWqGBU2 Small from screencast.com] * [http://www.screencast.com/t/x2iAx5..."

New page

The video from the lecture given on January 29, 2014 is available:
* [http://www.screencast.com/t/5lpc5qWqGBU2 Small from screencast.com]
* [http://www.screencast.com/t/x2iAx5KDyj Large from screencast.com]
* [http://dl.cuol.ca/capture/Anil.Somayaji/COMP_2406_2014W_Lecture_7_-_20140129_143752_27.mp4 Original from CUOL]