# Fixed query to create a 'users' table cursor.execute(''' CREATE TABLE IF NOT EXISTS users ( id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, age INTEGER ) ''') connection.commit() Use code with caution. 3. Executing "Fixed" Queries Python documentation
# Insert sample data safely sample_employees = [ ("Alice", "Engineering", 85000), ("Bob", "Marketing", 65000), ("Charlie", "Engineering", 91000), ] cursor.executemany("INSERT INTO employees (name, department, salary) VALUES (?, ?, ?)", sample_employees)
or use a with block to prevent locking.
Match exactly. Use (name, age) for two placeholders. sqlite3 tutorial query python fixed
. Suddenly, the bakery’s entire secret recipe list was exposed! Alex had fallen victim to a classic SQL injection attack Determined to it, Alex learned the golden rule of database security: never use string formatting (like f-strings or ) for queries The Fixed Tutorial Alex rewrote the code using parameterized queries . Here is the proper way to handle variables: Step 1: Use Placeholders
def main(): # Connect with row factory for named columns conn = sqlite3.connect('company.db') conn.row_factory = sqlite3.Row cursor = conn.cursor()
:
def add_user(name, email, age): with sqlite3.connect("my_database.db") as conn: cursor = conn.cursor() cursor.execute(""" INSERT INTO users (name, email, age) VALUES (?, ?, ?) """, (name, email, age)) # No need for explicit commit here (context manager does it)
Placeholders ( ? or :name ) can only replace . They cannot be used for table names or column names. If you need dynamic column names, you must safely validate them against an explicit whitelist in your Python code before constructing the query string. 3. Handle Exceptions Gracefully
# Create table cursor.execute(''' CREATE TABLE IF NOT EXISTS employees ( id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, department TEXT, salary REAL ) ''') # Fixed query to create a 'users' table cursor
When connecting, give SQLite more time to wait for a lock to clear. conn = sqlite3.connect('app_data.db', timeout=10)
class SafeQueryBuilder: """Builds dynamic WHERE clauses without SQL injection""" def __init__(self, base_query: str): self.base_query = base_query self.conditions = [] self.params = []
users_data = [ ("john_doe", "john@example.com", 25), ("jane_smith", "jane@example.com", 30), ("bob_wilson", "bob@example.com", 35), ("alice_johnson", "alice@example.com", 28) ] Match exactly