Vet clinic database: query and update table

data.sql

@@ -1,10 +1,25 @@
 SET datestyle = dmy;
 
-INSERT INTO animals(id, name, date_of_birth, escape_attempts, neutered, weight_kg)
-VALUES(1, 'Agumon','02/03/2020',0,true,10.23);
-INSERT INTO animals(id, name, date_of_birth, escape_attempts, neutered, weight_kg)
-VALUES(2, 'Gabumon','15/11/2018',2,true,8.0);
-INSERT INTO animals(id, name, date_of_birth, escape_attempts, neutered, weight_kg)
-VALUES(3, 'Pikachu','07/01/2021',1,false,15.04);
-INSERT INTO animals(id, name, date_of_birth, escape_attempts, neutered, weight_kg)
-VALUES(4, 'Devimon','12/05/2017',5,true,11.0);
+INSERT INTO animals(name, date_of_birth, escape_attempts, neutered, weight_kg)
+VALUES('Agumon','02/03/2020',0,true,10.23);
+
+INSERT INTO animals(name, date_of_birth, escape_attempts, neutered, weight_kg)
+VALUES('Gabumon','15/11/2018',2,true,8.0);
+INSERT INTO animals(name, date_of_birth, escape_attempts, neutered, weight_kg)
+VALUES('Pikachu','07/01/2021',1,false,15.04);
+INSERT INTO animals(name, date_of_birth, escape_attempts, neutered, weight_kg)
+VALUES('Devimon','12/05/2017',5,true,11.0);
+INSERT INTO animals(name, date_of_birth, escape_attempts, neutered, weight_kg)
+VALUES('Charmander','08/02/2020',0,false,-11.0);
+INSERT INTO animals(name, date_of_birth, escape_attempts, neutered, weight_kg)
+VALUES('Plantmon','15/11/2021',2,true,-5.7);
+INSERT INTO animals(name, date_of_birth, escape_attempts, neutered, weight_kg)
+VALUES('Squirtle','02/04/1993',3,false,-12.13);
+INSERT INTO animals(name, date_of_birth, escape_attempts, neutered, weight_kg)
+VALUES('Angemon','12/06/2005',1,true,-45.0);
+INSERT INTO animals(name, date_of_birth, escape_attempts, neutered, weight_kg)
+VALUES('Boarmon','07/06/2005',7,true,20.4);
+INSERT INTO animals(name, date_of_birth, escape_attempts, neutered, weight_kg)
+VALUES('Blossom','13/10/1998',3,true,17.0);
+INSERT INTO animals(name, date_of_birth, escape_attempts, neutered, weight_kg)
+VALUES('Ditto','14/05/2022',4,true,22.0);

queries.sql

@@ -24,4 +24,44 @@ SELECT * FROM animals
 WHERE name != 'Gabumon';
 
 SELECT * FROM animals
-WHERE weight_kg >= 10.4 AND weight_kg <= 17.3
+WHERE weight_kg >= 10.4 AND weight_kg <= 17.3
+
+-- queries to perform transaction
+
+BEGIN;
+UPDATE animals SET species = 'unspecified';
+ROLLBACK;
+
+BEGIN;
+UPDATE animals SET species = 'digimon' WHERE name like '%mon';
+UPDATE animals SET species = 'pokemon'WHERE species is null;
+COMMIT;
+
+BEGIN;
+DELETE FROM animals;
+ROLLBACK;
+
+BEGIN;
+DELETE FROM animals WHERE date_of_birth > '01/07/2022';
+SAVEPOINT savepoint_1;
+UPDATE animals SET weight_kg = (weight_kg * -1);
+ROLLBACK TO savepoint_1;
+UPDATE animals SET weight_kg =  (weight_kg * - 1) WHERE weight_kg < 0;
+COMMIT;
+
+--  queries to perform aggregate functions
+
+SELECT COUNT(*) FROM animals;
+
+SELECT COUNT(*) FROM animals WHERE escape_attempts = 0;
+
+SELECT AVG(weight_kg) FROM animals
+
+SELECT name FROM animals
+ORDER BY escape_attempts DESC LIMIT 1;
+
+SELECT MIN(weight_kg), MAX(weight_kg) FROM animals GROUP BY(species);
+
+SELECT ROUND(AVG(escape_attempts),2) AS average FROM animals
+WHERE EXTRACT(YEAR FROM date_of_birth) BETWEEN '1990' AND '2000'
+GROUP BY(species) ORDER BY average;

schema.sql

@@ -1,9 +1,12 @@
 /* Database schema to keep the structure of entire database. */
 CREATE TABLE animals(
-    id INTEGER NOT NULL PRIMARY KEY,
+    id SERIAL NOT NULL PRIMARY KEY,
     name VARCHAR(255) NOT NULL,
     date_of_birth DATE NOT NULL,
     escape_attempts integer NOT NULL,
     neutered BOOLEAN NOT NULL,
     weight_kg FLOAT NOT NULL	
-);
+);
+
+ALTER TABLE animals
+ADD COLUMN species VARCHAR(255);