Files
aii-monorepo/ejercicios/beautifulsoup/ej4/data/src/db.py

141 lines
4.1 KiB
Python

import sqlite3
from pathlib import Path
class DBAttr:
def __init__(self, name, type_, modifier=""):
self.name = name
self.type_ = type_
self.modifier = modifier
def sql(self):
parts = [self.name, self.type_]
if self.modifier:
parts.append(self.modifier)
return " ".join(parts)
class DBManager:
_instance = None
def __new__(cls, *args, **kwargs):
if cls._instance is None:
cls._instance = super().__new__(cls)
return cls._instance
def __init__(self, path):
self.path = Path(path)
self.conn = sqlite3.connect(self.path)
self.conn.row_factory = sqlite3.Row
def create_table(self, table_name, attributes: list[DBAttr]):
columns_sql = ",\n ".join(attr.sql() for attr in attributes)
query = f"""
CREATE TABLE IF NOT EXISTS {table_name} (
{columns_sql}
);
"""
try:
with self.conn:
self.conn.execute(query)
except Exception as e:
print("Error creating table:", e)
def get_all(self, table_name):
try:
cursor = self.conn.execute(f"SELECT * FROM {table_name};")
return [dict(row) for row in cursor.fetchall()]
except Exception as e:
print("Error selecting:", e)
return []
def get_singleton(self, singleton_table):
try:
cursor = self.conn.execute(f"SELECT * FROM {singleton_table}")
return [row[0] for row in cursor.fetchall()]
except Exception as e:
print("Error selecting:", e)
return []
def get_by(self, table_name, column, value):
try:
query = f"SELECT * FROM {table_name} WHERE {column} = ?;"
cursor = self.conn.execute(query, (value,))
return [dict(row) for row in cursor.fetchall()]
except Exception as e:
print("Error selecting:", e)
return []
def insert(self, table_name, data: dict):
keys = ", ".join(data.keys())
placeholders = ", ".join("?" for _ in data)
values = tuple(data.values())
query = f"""
INSERT INTO {table_name} ({keys})
VALUES ({placeholders});
"""
try:
with self.conn:
self.conn.execute(query, values)
except Exception as e:
print("Error inserting:", e)
def update(self, table_name, data: dict, where_column, where_value):
set_clause = ", ".join(f"{key} = ?" for key in data.keys())
values = list(data.values())
values.append(where_value)
query = f"""
UPDATE {table_name}
SET {set_clause}
WHERE {where_column} = ?;
"""
try:
with self.conn:
self.conn.execute(query, tuple(values))
except Exception as e:
print("Error updating:", e)
def delete(self, table_name, where_column, where_value):
query = f"DELETE FROM {table_name} WHERE {where_column} = ?;"
try:
with self.conn:
self.conn.execute(query, (where_value,))
except Exception as e:
print("Error deleting:", e)
def clear(self, table_name):
query = f"DELETE FROM {table_name};"
try:
with self.conn:
self.conn.execute(query)
except Exception as e:
print("Error clearing table: ", e)
def exists(self, table_name, where_column, where_value):
query = f"SELECT 1 FROM {table_name} WHERE {where_column} = ? LIMIT 1;"
try:
cursor = self.conn.execute(query, (where_value,))
return cursor.fetchone() is not None
except Exception as e:
print("Error checking existence:", e)
return False
def count(self, table_name):
try:
cursor = self.conn.execute(f"SELECT COUNT(*) as total FROM {table_name};")
return cursor.fetchone()["total"]
except Exception as e:
print("Error counting:", e)
return 0
def close(self):
self.conn.close()