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!

本练习是课程的一部分

Introduction to Databases in Python

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练习说明

Import delete and select from sqlalchemy.
Build a delete statement to remove all the data from the census table. Save it as delete_stmt.
Execute delete_stmt via the connection and save the results.
Submit the answer to select all remaining rows from the census table and print the result to confirm that the table is now empty!

交互式实操练习

通过完成这段示例代码来试试这个练习。

# 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())

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