Deleting all the records from a table
Often, you'll need to empty a table of all of its records so you can reload the
data. You can do this with a delete
statement with just the table as an argument. For example, in the video, Jason deleted the table extra_employees
by executing as follows:
delete_stmt = delete(extra_employees)
result_proxy = connection.execute(delete_stmt)
Do be careful, though, as deleting cannot be undone!
Cet exercice fait partie du cours
Introduction to Databases in Python
Instructions
- Import
delete
andselect
from sqlalchemy. - Build a
delete
statement to remove all the data from thecensus
table. Save it asdelete_stmt
. - Execute
delete_stmt
via theconnection
and save theresults
. - Submit the answer to
select
all remaining rows from thecensus
table and print the result to confirm that the table is now empty!
Exercice interactif pratique
Essayez cet exercice en complétant cet exemple de code.
# Import delete, select
from sqlalchemy import ____, ____
# Build a statement to empty the census table: stmt
delete_stmt = ____
# Execute the statement: results
results = ____
# Print affected rowcount
print(results.rowcount)
# Build a statement to select all records from the census table : select_stmt
select_stmt = select([census])
# Print the results of executing the statement to verify there are no rows
print(connection.execute(select_stmt).fetchall())