Create Table Of Elves
- Create table called elves CREATE TABLE elves ( - string variable name varchar(255), - integer variable age int, - string variable race varchar(255), - string variable alive varchar(255) )
Insert Rows Into Elf Table
INSERT INTO elves (name, age, race, alive) VALUES ('Dallar Woodfoot', 25, 'Elf', 'Yes'), ('Cordin Garner', 29, 'Elf', 'Yes'), ('Keat Knigh', 24, 'Elf', 'Yes'), ('Keat Knigh', 24, 'Elf', 'Yes'), ('Keat Knigh', 24, 'Elf', 'Yes'), ('Keat Knigh', 24, 'Elf', 'Yes'), ('Colbat Nalor', 124, 'Elf', 'Yes')
View Elves Table
- Retrieve all rows from the view Elf SELECT * FROM elves
Note: Normally we would use a unique identify column (e.g. person ID, product ID, etc.). However, since we don’t have a unique ID column we can use PostgreSQL’s internal system column,
ctid. Full documentation on
ctid and other system columns in avaliable here.
- Delete from the elves, calling it copy1 DELETE FROM elves copy1 - Using a second copy of elves, called copy2 USING elves copy2 - Where the internal PostgreSQL system column, ctid is smaller WHERE copy1.ctid < copy2.ctid - And all other columns are the same AND copy1.name = copy2.name AND copy1.age = copy2.age AND copy1.race = copy2.race AND copy1.alive = copy2.alive
Python Example for Beginners
Two Machine Learning Fields
There are two sides to machine learning:
- Practical Machine Learning:This is about querying databases, cleaning data, writing scripts to transform data and gluing algorithm and libraries together and writing custom code to squeeze reliable answers from data to satisfy difficult and ill defined questions. It’s the mess of reality.
- Theoretical Machine Learning: This is about math and abstraction and idealized scenarios and limits and beauty and informing what is possible. It is a whole lot neater and cleaner and removed from the mess of reality.
Data Science Resources: Data Science Recipes and Applied Machine Learning Recipes
Introduction to Applied Machine Learning & Data Science for Beginners, Business Analysts, Students, Researchers and Freelancers with Python & R Codes @ Western Australian Center for Applied Machine Learning & Data Science (WACAMLDS) !!!
Latest end-to-end Learn by Coding Recipes in Project-Based Learning:
Disclaimer: The information and code presented within this recipe/tutorial is only for educational and coaching purposes for beginners and developers. Anyone can practice and apply the recipe/tutorial presented here, but the reader is taking full responsibility for his/her actions. The author (content curator) of this recipe (code / program) has made every effort to ensure the accuracy of the information was correct at time of publication. The author (content curator) does not assume and hereby disclaims any liability to any party for any loss, damage, or disruption caused by errors or omissions, whether such errors or omissions result from accident, negligence, or any other cause. The information presented here could also be found in public knowledge domains.