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!
Bu egzersiz
Introduction to Databases in Python
kursunun bir parçasıdırEgzersiz talimatları
- Import
deleteandselectfrom sqlalchemy. - Build a
deletestatement to remove all the data from thecensustable. Save it asdelete_stmt. - Execute
delete_stmtvia theconnectionand save theresults. - Submit the answer to
selectall remaining rows from thecensustable and print the result to confirm that the table is now empty!
Uygulamalı interaktif egzersiz
Bu örnek kodu tamamlayarak bu egzersizi bitirin.
# 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())