MIS2502: Review for Exam 2. Jing Gong

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1 MIS2502: Review for Exam 2 Jing Gong gong@temple.edu

2 Overview Date/Time: Friday, October 30, 3:00 3:50 pm Place: Regular classroom (Alter Hall 232) Please arrive 5 minutes early! Multiple-choice and short-answer questions Closed-book, closed-note No computer

3 Multiple Choice Questions We will use the blue exam answer sheet. Bring #2 pencil and eraser. (Extra pencils will be provided)

4 ETL and Assignment 4 Extract data from the operational data store Transform data into an analysisready format Load it into the analytical data store What is it? Why is it important? Data consistency Data quality Explain the purpose of each component (Extract, Transform, Load) Excel functions VLOOKUP and CONCATENATE

5 Pivot Tables and Assignment 5 Given a question about a set of data, be able to identify the fields required to create a pivot table Identify which fields are assigned as VALUES and which ones are assigned as ROWS Identify the correct function for aggregation: i.e., SUM, COUNT, AVERAGE

6 SQL (Joins) SELECT * FROM moviedb.actor, moviedb.film, moviedb.film_actor WHERE actor.actor_id = film_actor.actor_id AND film.film_id = film_actor.film_id; hello

7 SQL (Joins) Who were the stars of the movie Operation Operation? SELECT actor.first_name, actor.last_name FROM moviedb.actor, moviedb.film, moviedb.film_actor WHERE actor.actor_id = film_actor.actor_id AND film.film_id = film_actor.film_id AND film.title = 'Operation Operation';

8 SQL (Subselects) Q: What is the shortest R-rated movie in French? And how long is it? Step 1: What is the length of the shortest R rated movie in French? SELECT MIN(film.length) FROM moviedb.film, moviedb.`language` WHERE film.language_id = `language`.language_id AND `language`.`name`='french' AND rating='r'; Step 2: Complete the query SELECT film.title, film.length FROM moviedb.film, moviedb.`language` WHERE film.language_id = `language`.language_id AND `language`.`name`='french' AND film.rating='r' AND film.length=( SELECT MIN(film.length) FROM moviedb.film, moviedb.`language` WHERE film.language_id = `language`.language_id AND `language`.`name`='french' AND rating='r );

9 SQL (CREATE TABLE) CREATE TABLE schema_name.table_name ( columnname1 datatype [NULL][NOT NULL], columnname2 datatype [NULL][NOT NULL], PRIMARY KEY (KeyName) ); Data type Description Examples INT Integer 3, -10 DECIMAL(p,s) VARCHAR(n) Decimal with p-s digits before the decimal and s digits after the decimal String (numbers and letters) with length n Q: What does DECIMAL(4, 1) indicate? A: The value cannot be larger than , Hello, I like pizza, MySQL! DATETIME Date/Time (or just date) :35:00, BOOLEAN Boolean value 0 or 1

10 SQL (DROP TABLE) DROP TABLE schema_name.table_name;

11 SQL (ALTER TABLE) ALTER TABLE schema_name.table_name ADD column_name datatype [NULL][NOT NULL]; or ALTER TABLE schema_name.table_name DROP COLUMN column_name; or ALTER TABLE schema_name.table_name CHANGE COLUMN old_column_name new_column_name datatype [NULL][NOT NULL]; Adds a column to the table Removes a column from the table Changes a column in the table

12 SQL (INSERT INTO, UPDATE, DELETE FROM) To insert a record into a table: INSERT INTO schema_name.table_name (columnname1, columnname2, columnname3) VALUES (value1, value2, value3); To change data in a row: UPDATE schema_name.table_name SET columnname1=value1, columnname2=value2 WHERE condition; To delete a row from a table: DELETE FROM schema_name.table_name WHERE condition;

13 Data Types Data type Description Examples INT Integer 3, -10 DECIMAL(p,s) VARCHAR(n) Decimal with p-s digits before the decimal and s digits after the decimal String (numbers and letters) with length n 3.23, Hello, I like pizza, MySQL! DATETIME Date/Time (or just date) :35:00, BOOLEAN Boolean value 0 or 1 Q: What does DECIMAL(4, 1) indicate? A: The value cannot be larger than 999.9

14 Data Visualization Be able to assess an infographic or chart by applying data visualization principles. Tell a story Graphical integrity (lie factor) Minimize graphical complexity (data ink, chartjunk) Explain how a visualization can be improved based on those principles.

15 Data Visualization For example How is the following chart deceptive?

Dimensional Data Modeling Data warehouse vs data mart vs data

Ardmore, PA Temple Main Cherry Hill, NJ Mar.

2012 Star schema Kimball s four step process for data mart design

16 Dimensional Data Modeling Data warehouse vs data mart vs data cube Product M&Ms Diet Coke Doritos Famous Amos Data Cube Store Ardmore, PA Temple Main Cherry Hill, NJ Mar King of Prussia, PA Jan Feb Star schema Kimball s four step process for data mart design 1. Choose the business process 3. Decide on the level of granularity 2. Identify the fact 4. Identify the dimensions

MIS2502: Review for Exam 2. Jing Gong

MIS2502: Review for Exam 2. Jing Gong MIS2502: Review for Exam 2 Jing Gong gong@temple.edu http://community.mis.temple.edu/gong Overview Date/Time: Thursday, March 24, in class (1 hour 20 minutes) Place: Regular classroom Please arrive 5 minutes