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79 lines
2.7 KiB
79 lines
2.7 KiB
-- Open up psql and create a sql_lab database if you haven't already done so.
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-- If you already have a sql_lab database, no need to create it again.
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-- Write SQL commands under the prompts below, and run the file to get results.
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-- In case there is already a computers table, drop it
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-- Create a computers table
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--###############
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--I added the delete command at the beginning when I want to rerun instead of having to enter commands manually. while debugging. But keep commented out if running whole thing to test.
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DROP DATABASE computers;
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---##############
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CREATE DATABASE computers;
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-- The table should have id, make, model, cpu_speed, memory_size,price, release_date, photo_url, storage_amount, number_usb_ports, number_firewire_ports, number_thunderbolt_ports);
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\connect computers;
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CREATE TABLE computers(id serial, make varchar(20), model varchar(20), cpu_speed int, memory_size int, price int, release_date timestamp, photo_url varchar(140), storage_amount int, number_usb_ports int, number_firewire_ports int, number_thunderbolt_ports int);
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-- Insert 4 computers into the computers table
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INSERT INTO computers(make, model, cpu_speed, memory_size, price, photo_url, storage_amount, number_usb_ports, number_firewire_ports, number_thunderbolt_ports) VALUES ('apple', 'desktop', 2200, 16, 2399, 'www.photo.com, 500', 8, 4, 2, 2);
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INSERT INTO computers(make, model, cpu_speed, memory_size, price) VALUES ('pc', 'laptop', 220, 8, 1250);
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INSERT INTO computers(make, model, price, release_date) VALUES ('pc', 'pixelbook', 677, '1981-12-01 22:33:44');
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--yyyy-mm-dd hh:mm:ss
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INSERT INTO computers(make, model, price) VALUES ('apple', 'macbook pro', 3000);
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-- Select all entries from the computers table
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--run here to show homework up to this point. and comment out this select all to run first part. otherwise keep it commented out.
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-- SELECT * FROM computers;
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-- HUNGRY FOR MORE?
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-- Look at this afternoon's instructor notes and read on altering tables before attempting below
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-- Alter the computers_models, removing the storage_amount column
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-- and add storage_type and storage_size columns
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ALTER TABLE computers DROP COLUMN storage_amount;
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ALTER TABLE computers ADD COLUMN storage_type varchar(50);
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ALTER TABLE computers ADD COLUMN storage_size int;
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-- ########NOTES#######
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--students will need to comment out first command and create table commands if they want to rerun code to debug. like for example if there are syntax errors.
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--they could get errors ERROR: relation "computers" already exists
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--another example ERROR: INSERT has more target columns than expressions
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SELECT * FROM computers;
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