dies. We need to remove him from the database: herb_mittens.delete_instance() # he had a great life # Returns: 1 Note: The return value of delete_instance() is the number of rows removed from the database 'Tennis Court 2')) Delete all bookings As part of a clearout of our database, we want to delete all bookings from the bookings table. DELETE FROM bookings; query = Booking.delete() Delete a member from from our database. DELETE FROM members WHERE memid = 37; query = Member.delete().where(Member.memid == 37) Delete based on a subquery How can we make that more general, to delete all members who have

dies. We need to remove him from the database: herb_mittens.delete_instance() # he had a great life # Returns: 1 Note: The return value of delete_instance() is the number of rows removed from the database 'Tennis Court 2')) Delete all bookings As part of a clearout of our database, we want to delete all bookings from the bookings table. DELETE FROM bookings; query = Booking.delete() Delete a member from from our database. DELETE FROM members WHERE memid = 37; query = Member.delete().where(Member.memid == 37) Delete based on a subquery How can we make that more general, to delete all members who have

Test Utils Flask Utils Query Builder Declaring tables Select queries Insert queries Update queries Delete queries More Hacks Optimistic Locking Top object per group Top N objects per group Writing custom dies. We need to remove him from the database: herb_mittens.delete_instance() # he had a great life # Returns: 1 Note The return value of delete_instance() is the number of rows removed from the database 'Tennis Court 2')) Delete all bookings As part of a clearout of our database, we want to delete all bookings from the bookings table. DELETE FROM bookings; query = Booking.delete() Delete a member from

Test Utils Flask Utils Query Builder Declaring tables Select queries Insert queries Update queries Delete queries Query Objects More Hacks Optimistic Locking Top object per group Top N objects per group dies. We need to remove him from the database: herb_mittens.delete_instance() # he had a great life # Returns: 1 Note The return value of delete_instance() is the number of rows removed from the database 'Tennis Court 2')) Delete all bookings As part of a clearout of our database, we want to delete all bookings from the bookings table. DELETE FROM bookings; query = Booking.delete() Delete a member from

dies. We need to remove him from the database: herb_mittens.delete_instance() # he had a great life # Returns: 1 Note: The return value of delete_instance() is the number of rows removed from the database peewee Documentation, Release 3.5.0 (continued from previous page) # Delete the user and their associated tweets. user.delete_instance(recursive=True) Transactions can be explicitly committed or rolled-back manager: with db.manual_commit(): db.begin() # Have to begin transaction explicitly. try: user.delete_instance(recursive=True) except: db.rollback() # Rollback! An error occurred. raise else: try:

Aggregation Recursion Query Builder Declaring tables Select queries Insert queries Update queries Delete queries Query Objects More Hacks Optimistic Locking Top object per group Top N objects per group dies. We need to remove him from the database: herb_mittens.delete_instance() # he had a great life # Returns: 1 Note The return value of delete_instance() is the number of rows removed from the database db = SqliteDatabase(':memory:') with db.transaction() as txn: # Delete the user and their associated tweets. user.delete_instance(recursive=True) Transactions can be explicitly committed or rolled-back

Test Utils Flask Utils Query Builder Declaring tables Select queries Insert queries Update queries Delete queries Query Objects More Hacks Optimistic Locking Top object per group Top N objects per group dies. We need to remove him from the database: herb_mittens.delete_instance() # he had a great life # Returns: 1 Note The return value of delete_instance() is the number of rows removed from the database 'Tennis Court 2')) Delete all bookings As part of a clearout of our database, we want to delete all bookings from the bookings table. DELETE FROM bookings; query = Booking.delete() Delete a member from

dies. We need to remove him from the database: herb_mittens.delete_instance() # he had a great life # Returns: 1 Note: The return value of delete_instance() is the number of rows removed from the database peewee Documentation, Release 3.6.0 (continued from previous page) # Delete the user and their associated tweets. user.delete_instance(recursive=True) Transactions can be explicitly committed or rolled-back manager: with db.manual_commit(): db.begin() # Have to begin transaction explicitly. try: user.delete_instance(recursive=True) except: db.rollback() # Rollback! An error occurred. raise else: try:

Aggregation Recursion Query Builder Declaring tables Select queries Insert queries Update queries Delete queries Query Objects More Hacks Optimistic Locking Top object per group Top N objects per group dies. We need to remove him from the database: herb_mittens.delete_instance() # he had a great life # Returns: 1 Note The return value of delete_instance() is the number of rows removed from the database db = SqliteDatabase(':memory:') with db.transaction() as txn: # Delete the user and their associated tweets. user.delete_instance(recursive=True) Transactions can be explicitly committed or rolled-back

UpdateQuery. Deleting a record To delete a single model instance, you can use the Model.delete_instance() shortcut: >>> user = User.get(User.id == 1) >>> user.delete_instance() 1 # <--- number of rows PARAMS: [1] To delete an arbitrary group of records, you can issue a DELETE query. The following will delete all Tweet objects that are a year old. >>> delete_query = Tweet.delete().where(Tweet.pub_date pub_date < one_year_ago) >>> delete_query.execute() 7 # <--- number of rows deleted For more information, see the documentation on DeleteQuery. Selecting a single record You can use the Model.get() method