Proyecto Intro SQL- Luis Alpizar

.gitignore

@@ -1,2 +1,2 @@
+.venv
 .env
-.learn

requirements.txt

@@ -4,6 +4,7 @@ pandas
 python-dotenv==0.20.0
 psycopg2-binary==2.9.3
 
+
 numpy>=1.18.5
 # opencv-python>=4.1.2
 # matplotlib>=3.2.2

src/app.py

@@ -1,90 +1,119 @@
 import os
 import pandas as pd
-from sqlalchemy import create_engine, text
 from dotenv import load_dotenv
+import sqlite3
 
 # Load environment variables
 load_dotenv()
 
-# 1) Connect to the database with SQLAlchemy
+# 1) Connect to the database with SQLite
 def connect():
     global engine
     try:
-        connection_string = f"postgresql://{os.getenv('DB_USER')}:{os.getenv('DB_PASSWORD')}@{os.getenv('DB_HOST')}/{os.getenv('DB_NAME')}"
-        print("Starting the connection...")
-        engine = create_engine(connection_string, isolation_level="AUTOCOMMIT") 
-        engine.connect()
-        print("Connected successfully!")
-        return engine
+        db_name = "database.db"  # Nombre de la base de datos SQLite
+        print("Iniciando conexión...")
+        conn = sqlite3.connect(db_name)  # Crear conexión
+        print("Conectado exitosamente!")
+        return conn
     except Exception as e:
-        print(f"Error connecting to the database: {e}")
+        print(f"Error al conectar a la base de datos: {e}")
         return None
 
-engine = connect()
+conn = connect()
 
-if engine is None:
+if conn is None:
     exit() 
 
 # 2) Create the tables
-with engine.connect() as connection:
-    connection.execute(text("""
+with conn:
+    conn.executescript("""
     CREATE TABLE IF NOT EXISTS publishers (
-        publisher_id SERIAL PRIMARY KEY,
-        name VARCHAR(255) NOT NULL
+        publisher_id INTEGER PRIMARY KEY AUTOINCREMENT,
+        name TEXT NOT NULL
     );
 
     CREATE TABLE IF NOT EXISTS authors (
-        author_id SERIAL PRIMARY KEY,
-        first_name VARCHAR(100) NOT NULL,
-        middle_name VARCHAR(50) NULL,
-        last_name VARCHAR(100) NULL
+        author_id INTEGER PRIMARY KEY AUTOINCREMENT,
+        first_name TEXT NOT NULL,
+        middle_name TEXT NULL,
+        last_name TEXT NULL
     );
 
     CREATE TABLE IF NOT EXISTS books (
-        book_id SERIAL PRIMARY KEY,
-        title VARCHAR(255) NOT NULL,
-        total_pages INT NULL,
-        rating DECIMAL(4, 2) NULL,
-        isbn VARCHAR(13) NULL,
+        book_id INTEGER PRIMARY KEY AUTOINCREMENT,
+        title TEXT NOT NULL,
+        total_pages INTEGER NULL,
+        rating REAL NULL,
+        isbn TEXT NULL,
         published_date DATE,
-        publisher_id INT NULL,
-        CONSTRAINT fk_publisher FOREIGN KEY (publisher_id) REFERENCES publishers(publisher_id) ON DELETE SET NULL
+        publisher_id INTEGER NULL,
+        FOREIGN KEY (publisher_id) REFERENCES publishers(publisher_id) ON DELETE SET NULL
     );
 
     CREATE TABLE IF NOT EXISTS book_authors (
-        book_id INT NOT NULL,
-        author_id INT NOT NULL,
+        book_id INTEGER NOT NULL,
+        author_id INTEGER NOT NULL,
         PRIMARY KEY (book_id, author_id),
-        CONSTRAINT fk_book FOREIGN KEY (book_id) REFERENCES books(book_id) ON DELETE CASCADE,
-        CONSTRAINT fk_author FOREIGN KEY (author_id) REFERENCES authors(author_id) ON DELETE CASCADE
+        FOREIGN KEY (book_id) REFERENCES books(book_id) ON DELETE CASCADE,
+        FOREIGN KEY (author_id) REFERENCES authors(author_id) ON DELETE CASCADE
     );
-    """))
+    """)
 
 # 3) Insert data
-with engine.connect() as connection:
-    connection.execute(text("""
-    INSERT INTO publishers (publisher_id, name) VALUES
+with conn:
+    conn.executescript("""
+    INSERT OR IGNORE INTO publishers (publisher_id, name) VALUES
         (1, 'O Reilly Media'),
         (2, 'A Book Apart'),
         (3, 'A K PETERS'),
         (4, 'Academic Press'),
         (5, 'Addison Wesley'),
         (6, 'Albert&Sweigart'),
-        (7, 'Alfred A. Knopf')
-    ON CONFLICT (publisher_id) DO NOTHING;
+        (7, 'Alfred A. Knopf');
 
-    INSERT INTO authors (author_id, first_name, middle_name, last_name) VALUES
+    INSERT OR IGNORE INTO authors (author_id, first_name, middle_name, last_name) VALUES
         (1, 'Merritt', NULL, 'Eric'),
         (2, 'Linda', NULL, 'Mui'),
         (3, 'Alecos', NULL, 'Papadatos'),
         (4, 'Anthony', NULL, 'Molinaro'),
         (5, 'David', NULL, 'Cronin'),
         (6, 'Richard', NULL, 'Blum'),
         (7, 'Yuval', 'Noah', 'Harari'),
-        (8, 'Paul', NULL, 'Albitz')
-    ON CONFLICT (author_id) DO NOTHING;
-    """))
+        (8, 'Paul', NULL, 'Albitz');
+
+    INSERT OR IGNORE INTO books (book_id, title, total_pages, rating, isbn, published_date, publisher_id) VALUES 
+        (1, 'Lean Software Development: An Agile Toolkit', 240, 4.17, '9780320000000', '2003-05-18', 5),
+        (2, 'Facing the Intelligence Explosion', 91, 3.87, NULL, '2013-02-01', 7),
+        (3, 'Scala in Action', 419, 3.74, '9781940000000', '2013-04-10', 1),
+        (4, 'Patterns of Software: Tales from the Software Community', 256, 3.84, '9780200000000', '1996-08-15', 1),
+        (5, 'Anatomy Of LISP', 446, 4.43, '9780070000000', '1978-01-01', 3),
+        (6, 'Computing machinery and intelligence', 24, 4.17, NULL, '2009-03-22', 4),
+        (7, 'XML: Visual QuickStart Guide', 269, 3.66, '9780320000000', '2009-01-01', 5),
+        (8, 'SQL Cookbook', 595, 3.95, '9780600000000', '2005-12-01', 7),
+        (9, 'The Apollo Guidance Computer: Architecture And Operation (Springer Praxis Books / Space Exploration)', 439, 4.29, '9781440000000', '2010-07-01', 6),
+        (10, 'Minds and Computers: An Introduction to the Philosophy of Artificial Intelligence', 222, 3.54, '9780750000000', '2007-02-13', 7);
+
+    INSERT OR IGNORE INTO book_authors (book_id, author_id) VALUES 
+        (1, 1),
+        (2, 8),
+        (3, 7),
+        (4, 6),
+        (5, 5),
+        (6, 4),
+        (7, 3),
+        (8, 2),
+        (9, 4),
+        (10, 1);         
+
+
+
+    """)
 
 # 4) Use Pandas to read and display a table
-df = pd.read_sql("SELECT * FROM publishers;", engine)
-print(df)
+df_books = pd.read_sql("SELECT * FROM books;", conn)
+
+print("\nLibros:")
+print(df_books)
+
+# 5) Close connection
+conn.close()