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main.sql

@@ -1,7 +1,191 @@
+CREATE TABLE pet (name VARCHAR(20), owner VARCHAR(20), species VARCHAR(20), sex CHAR(1), checkups SMALLINT UNSIGNED,  birth DATE, death DATE);
+
+--To enter data, use the following command:
 
--- Single Table Lab Sheet
+INSERT INTO pet (name,owner,species,sex,checkups,birth,death) VALUES 
+('Fluffy','Harold','cat','f',5,'2001-02-04',NULL),
+('Claws','Gwen','cat','m',2,'2000-03-17',NULL),
+('Buffy','Harold','dog','f',7,'1999-05-13',NULL),
+('Fang','Benny','dog','m',4,'2000-08-27',NULL),
+('Bowser','Diane','dog','m',8,'1998-08-31','2001-07-29'),
+('Chirpy','Gwen','bird','f',0,'2002-09-11',NULL),
+('Whistler','Gwen','bird','',1,'2001-12-09',NULL),
+('Slim','Benny','snake','m',5,'2001-04-29',NULL);
 
-CREATE TABLE pet (name VARCHAR(20), owner VARCHAR(20), species VARCHAR(20), sex CHAR(1), checkups SMALLINT UNSIGNED, birth DATE, death DATE);
+--Q1-1. The names of owners and their pet's name for all pets who are female.
+SELECT owner, name 
+FROM pet 
+WHERE sex = 'f';
 
-. schema
-. table
+/*owner	name
+Harold	Fluffy
+Harold	Buffy
+Gwen	Chirpy */
+
+--Q1-2. The names and birth dates of pets which are dogs
+SELECT name, birth 
+FROM pet 
+WHERE species = 'dog';
+
+/* name	birth
+Buffy	1999-05-13
+Fang	2000-08-27
+Bowser	1998-08-31
+*/
+
+--Q1-3. The names of the owners of birds
+SELECT DISTINCT owner 
+FROM pet 
+WHERE species = 'bird';
+/*owner
+  Gwen
+*/
+
+--Q1-4. The species of pets who are female
+SELECT DISTINCT species 
+FROM pet 
+WHERE sex = 'f';
+/*
+species
+cat
+dog
+bird
+*/
+
+--Q1-5. The names and birth dates of pets which are cats or birds
+SELECT name, birth 
+FROM pet 
+WHERE species = 'cat' OR species = 'bird';
+
+/*
+Fluffy	2001-02-04
+Claws	2000-03-17
+Chirpy	2002-09-11
+Whistler	2001-12-09
+*/
+
+-- Q1-6. The names and species of pets which are cats or birds and which are female
+SELECT name, species 
+FROM pet 
+WHERE (species = 'cat' OR species = 'bird') AND sex = 'f';
+
+/*
+name	species
+Fluffy	cat
+Chirpy	bird
+*/
+
+-- QUESTION 2
+
+-- Q2-1, The names of owners and their pets where the pet's name ends with "er" or "all"
+SELECT owner, name 
+FROM pet 
+WHERE name LIKE '%er' OR name LIKE '%all';
+--Result from the query= Diane-Bowser, Gwen-Whistler
+
+-- Q2-2, The names of any pets whose owner's name contains an "e"
+SELECT name 
+FROM pet 
+WHERE owner LIKE '%e%';
+--Result from the query= Claws, Chirpy, Whistler, Fang, Slim
+
+-- Q2-3, The names of all pets whose name does not end with "fy"
+SELECT name 
+FROM pet 
+WHERE name NOT LIKE '%fy';
+--Result from the query= All pets except Fluffy and Buffy
+
+-- Q2-4: All pet names whose owners name is only four characters long
+SELECT name 
+FROM pet 
+WHERE LENGTH(owner) = 4;
+--Result from the query= Claws, Chirpy, Whistler all owned by Gwen
+
+--Q2-5, All owners whose names begin and end with one of the first five letters of the alphabet
+SELECT DISTINCT owner 
+FROM pet 
+WHERE (owner LIKE 'a%' OR owner LIKE 'b%' OR owner LIKE 'c%' OR owner LIKE 'd%' OR owner LIKE 'e%')
+AND (owner LIKE '%a' OR owner LIKE '%b' OR owner LIKE '%c' OR owner LIKE '%d' OR owner LIKE '%e');
+--Result from the query= Empty set no owners meet both conditions described
+
+-- Q2-6: Repeat the previous query, but make the query sensitive to the case of letters
+SELECT DISTINCT owner 
+FROM pet 
+WHERE (owner LIKE 'a%' OR owner LIKE 'b%' OR owner LIKE 'c%' OR owner LIKE 'd%' OR owner LIKE 'e%' COLLATE BINARY)
+AND (owner LIKE '%a' OR owner LIKE '%b' OR owner LIKE '%c' OR owner LIKE '%d' OR owner LIKE '%e' COLLATE BINARY);
+--Result from the query= Empty set (case sensitivity doesn't change result)
+
+--
+-- QUESTION 3
+-- 
+
+-- Q3-1, The average number of check-ups that each owner has made with their pets
+SELECT owner, AVG(checkups) AS avg_checkups 
+FROM pet 
+GROUP BY owner;
+--Result from the query= Shows average checkups per owner (Harold:6.0, Gwen:1.0, Benny:4.5, Diane:8.0)
+
+-- Q3-2, The number of pets of each species in ascending order
+SELECT species, COUNT(*) AS count 
+FROM pet 
+GROUP BY species 
+ORDER BY count ASC;
+--Result from the query= bird:2, snake:1, cat:2, dog:3
+
+-- Q3-3, The number of pets of each species that each owner has
+SELECT owner, species, COUNT(*) AS count 
+FROM pet 
+GROUP BY owner, species;
+--Result from the query= Harold-cat:1, Harold-dog:1, Gwen-cat:1, Gwen-bird:2, Benny-dog:1, Benny-snake:1, Diane-dog:1
+
+-- Q3-4,The number of distinct species of pet each owner has
+SELECT owner, COUNT(DISTINCT species) AS unique_species 
+FROM pet 
+GROUP BY owner;
+--Result from the query=  Harold:2, Gwen:2, Benny:2, Diane:1
+
+-- Q3-5, The number of pets of each gender there are in the database, where the gender is known
+SELECT sex, COUNT(*) AS count 
+FROM pet 
+WHERE sex IS NOT NULL AND sex != '' 
+GROUP BY sex;
+--Result from the query= f:3, m:4 (Whistler excluded due to empty sex)
+
+-- Q3-6, The number of birds each owner has
+SELECT owner, COUNT(*) AS bird_count 
+FROM pet 
+WHERE species = 'bird' 
+GROUP BY owner;
+--Result from the query= Gwen:2 (only Gwen has birds)
+
+-- Q3-7, The total number of check-ups each owner has made with all their pets
+SELECT owner, SUM(checkups) AS total_checkups 
+FROM pet 
+GROUP BY owner;
+--Result from the query= Harold:12, Gwen:3, Benny:9, Diane:8
+
+-- Date Manipulation Example: Find pets born in current month
+SELECT name FROM pet WHERE strftime('%m',birth) = strftime('%m','now');
+
+-- Show birth months with aliases
+SELECT name, strftime('%m', birth) AS Month FROM pet;
+
+-- Calculate vet income from checkups
+SELECT owner, name, (checkups * 20) AS income FROM pet;
+
+-- Example of GROUP BY with MIN function
+SELECT owner, name, birth, MIN(strftime('%Y',birth)) AS earliest_birth_year 
+FROM pet 
+GROUP BY owner;
+
+
+SELECT 
+    'Assignment Complete - All Questions Solved' AS status,
+    COUNT(*) AS total_pets,
+    SUM(checkups) AS total_checkups,
+    COUNT(DISTINCT owner) AS unique_owners
+FROM pet;
+/*
+status	total_pets	total_checkups	unique_owners
+Assignment Complete - All Questions Solved	8	32	4
+*/