A database result set is the table of rows and columns produced when a database executes a query. It can contain filtered rows, counts, or other aggregate results. section 5.2.2
A result set commonly appears after a query:
- A SELECT statement chooses columns or aggregates from one or more tables. section 5.2.2
- FROM identifies the source tables, while WHERE restricts which rows are considered. section 5.2.2
- Python's sqlite3 cursor retrieves the result rows with fetchall(), returning them as a list. section 5.3.1
Retrieving rows from SQLite
A reusable process_query function connects to the database, creates a cursor, executes the supplied query, retrieves the rows, converts each row to text, and joins the rows with newline separators. section 5.3.1
def process_query(data_path, query):
with sqlite3.connect(data_path) as connection: #1
cursor = connection.cursor() #2
cursor.execute(query) #3
table_rows = cursor.fetchall() #4
#5
table_strings = [str(r) for r in table_rows]
return '\n'.join(table_strings) #6
Follow the complete Python workflow from database connection through cursor execution, fetchall(), row conversion, and formatted output. section 5.3.1
