Chapter 10 and Try it Yourself updates
This commit is contained in:
anthonydb
parent
0187dbae32
commit
babfab494a
@ -8,8 +8,8 @@
|
||||
-- Listing 10-1: Importing the FSIS Meat, Poultry, and Egg Inspection Directory
|
||||
-- https://catalog.data.gov/dataset/fsis-meat-poultry-and-egg-inspection-directory-by-establishment-name
|
||||
|
||||
CREATE TABLE meat_poultry_egg_inspect (
|
||||
est_number text CONSTRAINT est_number_key PRIMARY KEY,
|
||||
CREATE TABLE meat_poultry_egg_establishments (
|
||||
establishment_number text CONSTRAINT est_number_key PRIMARY KEY,
|
||||
company text,
|
||||
street text,
|
||||
city text,
|
||||
@ -21,14 +21,15 @@ CREATE TABLE meat_poultry_egg_inspect (
|
||||
dbas text
|
||||
);
|
||||
|
||||
COPY meat_poultry_egg_inspect
|
||||
FROM 'C:\YourDirectory\MPI_Directory_by_Establishment_Name.csv'
|
||||
WITH (FORMAT CSV, HEADER, DELIMITER ',');
|
||||
COPY meat_poultry_egg_establishments
|
||||
-- FROM 'C:\YourDirectory\MPI_Directory_by_Establishment_Name.csv'
|
||||
from '/Users/adebarros/Dropbox/DataMonky/Book-Writing/PracticalSQL_2e/Code-Repo/Chapter_10/MPI_Directory_by_Establishment_Name.csv'
|
||||
WITH (FORMAT CSV, HEADER);
|
||||
|
||||
CREATE INDEX company_idx ON meat_poultry_egg_inspect (company);
|
||||
CREATE INDEX company_idx ON meat_poultry_egg_establishments (company);
|
||||
|
||||
-- Count the rows imported:
|
||||
SELECT count(*) FROM meat_poultry_egg_inspect;
|
||||
SELECT count(*) FROM meat_poultry_egg_establishments;
|
||||
|
||||
-- Listing 10-2: Finding multiple companies at the same address
|
||||
SELECT company,
|
||||
@ -36,7 +37,7 @@ SELECT company,
|
||||
city,
|
||||
st,
|
||||
count(*) AS address_count
|
||||
FROM meat_poultry_egg_inspect
|
||||
FROM meat_poultry_egg_establishments
|
||||
GROUP BY company, street, city, st
|
||||
HAVING count(*) > 1
|
||||
ORDER BY company, street, city, st;
|
||||
@ -44,24 +45,24 @@ ORDER BY company, street, city, st;
|
||||
-- Listing 10-3: Grouping and counting states
|
||||
SELECT st,
|
||||
count(*) AS st_count
|
||||
FROM meat_poultry_egg_inspect
|
||||
FROM meat_poultry_egg_establishments
|
||||
GROUP BY st
|
||||
ORDER BY st;
|
||||
|
||||
-- Listing 10-4: Using IS NULL to find missing values in the st column
|
||||
SELECT est_number,
|
||||
SELECT establishment_number,
|
||||
company,
|
||||
city,
|
||||
st,
|
||||
zip
|
||||
FROM meat_poultry_egg_inspect
|
||||
FROM meat_poultry_egg_establishments
|
||||
WHERE st IS NULL;
|
||||
|
||||
-- Listing 10-5: Using GROUP BY and count() to find inconsistent company names
|
||||
|
||||
SELECT company,
|
||||
count(*) AS company_count
|
||||
FROM meat_poultry_egg_inspect
|
||||
FROM meat_poultry_egg_establishments
|
||||
GROUP BY company
|
||||
ORDER BY company ASC;
|
||||
|
||||
@ -69,7 +70,7 @@ ORDER BY company ASC;
|
||||
|
||||
SELECT length(zip),
|
||||
count(*) AS length_count
|
||||
FROM meat_poultry_egg_inspect
|
||||
FROM meat_poultry_egg_establishments
|
||||
GROUP BY length(zip)
|
||||
ORDER BY length(zip) ASC;
|
||||
|
||||
@ -77,151 +78,160 @@ ORDER BY length(zip) ASC;
|
||||
|
||||
SELECT st,
|
||||
count(*) AS st_count
|
||||
FROM meat_poultry_egg_inspect
|
||||
FROM meat_poultry_egg_establishments
|
||||
WHERE length(zip) < 5
|
||||
GROUP BY st
|
||||
ORDER BY st ASC;
|
||||
|
||||
-- Listing 10-8: Backing up a table
|
||||
|
||||
CREATE TABLE meat_poultry_egg_inspect_backup AS
|
||||
SELECT * FROM meat_poultry_egg_inspect;
|
||||
CREATE TABLE meat_poultry_egg_establishments_backup AS
|
||||
SELECT * FROM meat_poultry_egg_establishments;
|
||||
|
||||
-- Check number of records:
|
||||
SELECT
|
||||
(SELECT count(*) FROM meat_poultry_egg_inspect) AS original,
|
||||
(SELECT count(*) FROM meat_poultry_egg_inspect_backup) AS backup;
|
||||
(SELECT count(*) FROM meat_poultry_egg_establishments) AS original,
|
||||
(SELECT count(*) FROM meat_poultry_egg_establishments_backup) AS backup;
|
||||
|
||||
-- Listing 10-9: Creating and filling the st_copy column with ALTER TABLE and UPDATE
|
||||
|
||||
ALTER TABLE meat_poultry_egg_inspect ADD COLUMN st_copy varchar(2);
|
||||
ALTER TABLE meat_poultry_egg_establishments ADD COLUMN st_copy text;
|
||||
|
||||
UPDATE meat_poultry_egg_inspect
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET st_copy = st;
|
||||
|
||||
-- Listing 10-10: Checking values in the st and st_copy columns
|
||||
|
||||
SELECT st,
|
||||
st_copy
|
||||
FROM meat_poultry_egg_inspect
|
||||
FROM meat_poultry_egg_establishments
|
||||
ORDER BY st;
|
||||
|
||||
-- With WHERE clause to check for equality
|
||||
SELECT st,
|
||||
st_copy
|
||||
FROM meat_poultry_egg_establishments
|
||||
WHERE st <> st_copy
|
||||
ORDER BY st;
|
||||
|
||||
-- Listing 10-11: Updating the st column for three establishments
|
||||
|
||||
UPDATE meat_poultry_egg_inspect
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET st = 'MN'
|
||||
WHERE est_number = 'V18677A';
|
||||
WHERE establishment_number = 'V18677A';
|
||||
|
||||
UPDATE meat_poultry_egg_inspect
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET st = 'AL'
|
||||
WHERE est_number = 'M45319+P45319';
|
||||
WHERE establishment_number = 'M45319+P45319';
|
||||
|
||||
UPDATE meat_poultry_egg_inspect
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET st = 'WI'
|
||||
WHERE est_number = 'M263A+P263A+V263A';
|
||||
WHERE establishment_number = 'M263A+P263A+V263A';
|
||||
|
||||
-- Listing 10-12: Restoring original st column values
|
||||
|
||||
-- Restoring from the column backup
|
||||
UPDATE meat_poultry_egg_inspect
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET st = st_copy;
|
||||
|
||||
-- Restoring from the table backup
|
||||
UPDATE meat_poultry_egg_inspect original
|
||||
UPDATE meat_poultry_egg_establishments original
|
||||
SET st = backup.st
|
||||
FROM meat_poultry_egg_inspect_backup backup
|
||||
WHERE original.est_number = backup.est_number;
|
||||
FROM meat_poultry_egg_establishments_backup backup
|
||||
WHERE original.establishment_number = backup.establishment_number;
|
||||
|
||||
-- Listing 10-13: Creating and filling the company_standard column
|
||||
|
||||
ALTER TABLE meat_poultry_egg_inspect ADD COLUMN company_standard varchar(100);
|
||||
ALTER TABLE meat_poultry_egg_establishments ADD COLUMN company_standard text;
|
||||
|
||||
UPDATE meat_poultry_egg_inspect
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET company_standard = company;
|
||||
|
||||
-- Listing 10-14: Use UPDATE to modify field values that match a string
|
||||
-- Listing 10-14: Use UPDATE to modify column values that match a string
|
||||
|
||||
UPDATE meat_poultry_egg_inspect
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET company_standard = 'Armour-Eckrich Meats'
|
||||
WHERE company LIKE 'Armour%';
|
||||
|
||||
SELECT company, company_standard
|
||||
FROM meat_poultry_egg_inspect
|
||||
FROM meat_poultry_egg_establishments
|
||||
WHERE company LIKE 'Armour%';
|
||||
|
||||
-- Listing 10-15: Creating and filling the zip_copy column
|
||||
|
||||
ALTER TABLE meat_poultry_egg_inspect ADD COLUMN zip_copy varchar(5);
|
||||
ALTER TABLE meat_poultry_egg_establishments ADD COLUMN zip_copy text;
|
||||
|
||||
UPDATE meat_poultry_egg_inspect
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET zip_copy = zip;
|
||||
|
||||
-- Listing 10-16: Modify codes in the zip column missing two leading zeros
|
||||
|
||||
UPDATE meat_poultry_egg_inspect
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET zip = '00' || zip
|
||||
WHERE st IN('PR','VI') AND length(zip) = 3;
|
||||
|
||||
-- Listing 10-17: Modify codes in the zip column missing one leading zero
|
||||
|
||||
UPDATE meat_poultry_egg_inspect
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET zip = '0' || zip
|
||||
WHERE st IN('CT','MA','ME','NH','NJ','RI','VT') AND length(zip) = 4;
|
||||
|
||||
-- Listing 10-18: Creating and filling a state_regions table
|
||||
|
||||
CREATE TABLE state_regions (
|
||||
st varchar(2) CONSTRAINT st_key PRIMARY KEY,
|
||||
region varchar(20) NOT NULL
|
||||
st text CONSTRAINT st_key PRIMARY KEY,
|
||||
region text NOT NULL
|
||||
);
|
||||
|
||||
COPY state_regions
|
||||
FROM 'C:\YourDirectory\state_regions.csv'
|
||||
WITH (FORMAT CSV, HEADER, DELIMITER ',');
|
||||
-- FROM 'C:\YourDirectory\state_regions.csv'
|
||||
from '/Users/adebarros/Dropbox/DataMonky/Book-Writing/PracticalSQL_2e/Code-Repo/Chapter_10/state_regions.csv'
|
||||
WITH (FORMAT CSV, HEADER);
|
||||
|
||||
-- Listing 10-19: Adding and updating an inspection_date column
|
||||
-- Listing 10-19: Adding and updating an inspection_deadline column
|
||||
|
||||
ALTER TABLE meat_poultry_egg_inspect ADD COLUMN inspection_date date;
|
||||
ALTER TABLE meat_poultry_egg_establishments
|
||||
ADD COLUMN inspection_deadline timestamp with time zone;
|
||||
|
||||
UPDATE meat_poultry_egg_inspect inspect
|
||||
SET inspection_date = '20110-12-01'
|
||||
UPDATE meat_poultry_egg_establishments establishments
|
||||
SET inspection_deadline = '2022-12-01 00:00 EST'
|
||||
WHERE EXISTS (SELECT state_regions.region
|
||||
FROM state_regions
|
||||
WHERE inspect.st = state_regions.st
|
||||
WHERE establishments.st = state_regions.st
|
||||
AND state_regions.region = 'New England');
|
||||
|
||||
-- Listing 10-20: Viewing updated inspection_date values
|
||||
-- Listing 10-20: Viewing updated inspection_deadline values
|
||||
|
||||
SELECT st, inspection_date
|
||||
FROM meat_poultry_egg_inspect
|
||||
GROUP BY st, inspection_date
|
||||
SELECT st, inspection_deadline
|
||||
FROM meat_poultry_egg_establishments
|
||||
GROUP BY st, inspection_deadline
|
||||
ORDER BY st;
|
||||
|
||||
-- Listing 10-21: Delete rows matching an expression
|
||||
|
||||
DELETE FROM meat_poultry_egg_inspect
|
||||
WHERE st IN('PR','VI');
|
||||
DELETE FROM meat_poultry_egg_establishments
|
||||
WHERE st IN('AS','GU','MP','PR','VI');
|
||||
|
||||
-- Listing 10-22: Remove a column from a table using DROP
|
||||
|
||||
ALTER TABLE meat_poultry_egg_inspect DROP COLUMN zip_copy;
|
||||
ALTER TABLE meat_poultry_egg_establishments DROP COLUMN zip_copy;
|
||||
|
||||
-- Listing 10-23: Remove a table from a database using DROP
|
||||
|
||||
DROP TABLE meat_poultry_egg_inspect_backup;
|
||||
DROP TABLE meat_poultry_egg_establishments_backup;
|
||||
|
||||
-- Listing 10-24: Demonstrating a transaction block
|
||||
|
||||
-- Start transaction and perform update
|
||||
START TRANSACTION;
|
||||
|
||||
UPDATE meat_poultry_egg_inspect
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET company = 'AGRO Merchantss Oakland LLC'
|
||||
WHERE company = 'AGRO Merchants Oakland, LLC';
|
||||
|
||||
-- view changes
|
||||
SELECT company
|
||||
FROM meat_poultry_egg_inspect
|
||||
FROM meat_poultry_egg_establishments
|
||||
WHERE company LIKE 'AGRO%'
|
||||
ORDER BY company;
|
||||
|
||||
@ -230,14 +240,14 @@ ROLLBACK;
|
||||
|
||||
-- See restored state
|
||||
SELECT company
|
||||
FROM meat_poultry_egg_inspect
|
||||
FROM meat_poultry_egg_establishments
|
||||
WHERE company LIKE 'AGRO%'
|
||||
ORDER BY company;
|
||||
|
||||
-- Alternately, commit changes at the end:
|
||||
START TRANSACTION;
|
||||
|
||||
UPDATE meat_poultry_egg_inspect
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET company = 'AGRO Merchants Oakland LLC'
|
||||
WHERE company = 'AGRO Merchants Oakland, LLC';
|
||||
|
||||
@ -245,15 +255,15 @@ COMMIT;
|
||||
|
||||
-- Listing 10-25: Backing up a table while adding and filling a new column
|
||||
|
||||
CREATE TABLE meat_poultry_egg_inspect_backup AS
|
||||
CREATE TABLE meat_poultry_egg_establishments_backup AS
|
||||
SELECT *,
|
||||
'2018-02-07'::date AS reviewed_date
|
||||
FROM meat_poultry_egg_inspect;
|
||||
'2023-02-14 00:00 EST'::timestamp with time zone AS reviewed_date
|
||||
FROM meat_poultry_egg_establishments;
|
||||
|
||||
-- Listing 10-26: Swapping table names using ALTER TABLE
|
||||
|
||||
ALTER TABLE meat_poultry_egg_inspect RENAME TO meat_poultry_egg_inspect_temp;
|
||||
ALTER TABLE meat_poultry_egg_inspect_backup RENAME TO meat_poultry_egg_inspect;
|
||||
ALTER TABLE meat_poultry_egg_inspect_temp RENAME TO meat_poultry_egg_inspect_backup;
|
||||
ALTER TABLE meat_poultry_egg_establishments RENAME TO meat_poultry_egg_establishments_temp;
|
||||
ALTER TABLE meat_poultry_egg_establishments_backup RENAME TO meat_poultry_egg_establishments;
|
||||
ALTER TABLE meat_poultry_egg_establishments_temp RENAME TO meat_poultry_egg_establishments_backup;
|
||||
|
||||
|
||||
|
||||
@ -607,3 +607,59 @@ WHERE pls16.fscskey IS NULL OR pls17.fscskey IS NULL;
|
||||
|
||||
-- Note: The IS NULL statements in the WHERE clause limit results to those
|
||||
-- that do not appear in one or more tables.
|
||||
|
||||
--------------------------------------------------------------
|
||||
-- Chapter 10: Inspecting and Modifying Data
|
||||
--------------------------------------------------------------
|
||||
|
||||
-- In this exercise, you’ll turn the meat_poultry_egg_inspect table into useful
|
||||
-- information. You needed to answer two questions: How many of the companies
|
||||
-- in the table process meat, and how many process poultry?
|
||||
|
||||
-- Create two new columns called meat_processing and poultry_processing. Each
|
||||
-- can be of the type boolean.
|
||||
|
||||
-- Using UPDATE, set meat_processing = TRUE on any row where the activities
|
||||
-- column contains the text 'Meat Processing'. Do the same update on the
|
||||
-- poultry_processing column, but this time lookup for the text
|
||||
-- 'Poultry Processing' in activities.
|
||||
|
||||
-- Use the data from the new, updated columns to count how many companies
|
||||
-- perform each type of activity. For a bonus challenge, count how many
|
||||
-- companies perform both activities.
|
||||
|
||||
-- Answer:
|
||||
-- a) Add the columns
|
||||
|
||||
ALTER TABLE meat_poultry_egg_establishments ADD COLUMN meat_processing boolean;
|
||||
ALTER TABLE meat_poultry_egg_establishments ADD COLUMN poultry_processing boolean;
|
||||
|
||||
SELECT * FROM meat_poultry_egg_establishments; -- view table with new empty columns
|
||||
|
||||
-- b) Update the columns
|
||||
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET meat_processing = TRUE
|
||||
WHERE activities ILIKE '%meat processing%'; -- case-insensitive match with wildcards
|
||||
|
||||
UPDATE meat_poultry_egg_establishments
|
||||
SET poultry_processing = TRUE
|
||||
WHERE activities ILIKE '%poultry processing%'; -- case-insensitive match with wildcards
|
||||
|
||||
-- c) view the updated table
|
||||
|
||||
SELECT * FROM meat_poultry_egg_establishments;
|
||||
|
||||
-- d) Count meat and poultry processors
|
||||
|
||||
SELECT count(meat_processing), count(poultry_processing)
|
||||
FROM meat_poultry_egg_establishments;
|
||||
|
||||
-- e) Count those who do both
|
||||
|
||||
SELECT count(*)
|
||||
FROM meat_poultry_egg_establishments
|
||||
WHERE meat_processing = TRUE AND
|
||||
poultry_processing = TRUE;
|
||||
|
||||
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user