Window functions Retrieving raw tuples / dictionaries Returning Clause Query operators Three valued logic Adding user-defined operators Expressions Foreign Keys Traversing foreign keys Joining tables Implementing in its own transaction. That is going to be really slow! 2. There is a decent amount of Python logic getting in your way, and each InsertQuery must be generated and parsed into SQL. 3. That’s a lot to retrieve the matching row. Failing that, a new row will be created. For “create or get” type logic, typically one would rely on a unique constraint or primary key to prevent the creation of duplicate

Retrieving row tuples / dictionaries / namedtuples Returning Clause Query operators Three valued logic Adding user-defined operators Expressions Foreign Keys Traversing foreign keys Joining tables Implementing bookings, using a subquery The “Produce a list of costly bookings” exercise contained some messy logic: we had to calculate the booking cost in both the WHERE clause and the CASE statement. Try to simplify happens in its own transaction. That is going to be really slow! 2. There is a decent amount of Python logic getting in your way, and each InsertQuery must be generated and parsed into SQL. 3. That’s a lot

happens in its own transaction. That is going to be really slow! 2. There is a decent amount of Python logic getting in your way, and each InsertQuery must be generated and parsed into SQL. 3. That’s a lot to retrieve the matching row. Failing that, a new row will be created. For “create or get” type logic, typically one would rely on a unique constraint or primary key to prevent the creation of duplicate call .get(). return User.get(User.username == username) You can easily encapsulate this type of logic as a classmethod on your own Model classes. The above example first attempts at creation, then falls

Joins Implementing Many to Many Self-joins Performance Techniques Query operators Three valued logic Adding user-defined operators Expressions SQL Functions SQL Helper Security and SQL Injection API happens in its own transaction. That is going to be really slow! 2. There is a decent amount of Python logic getting in your way, and each InsertQuery must be generated and parsed into SQL. 3. That’s a lot to retrieve the matching row. Failing that, a new row will be created. For “create or get” type logic, typically one would rely on a unique constraint or primary key to prevent the creation of duplicate

Retrieving row tuples / dictionaries / namedtuples Returning Clause Query operators Three valued logic Adding user-defined operators Expressions Foreign Keys Traversing foreign keys Joining tables Implementing bookings, using a subquery The “Produce a list of costly bookings” exercise contained some messy logic: we had to calculate the booking cost in both the WHERE clause and the CASE statement. Try to simplify happens in its own transaction. That is going to be really slow! 2. There is a decent amount of Python logic getting in your way, and each InsertQuery must be generated and parsed into SQL. 3. That’s a lot

Retrieving row tuples / dictionaries / namedtuples Returning Clause Query operators Three valued logic Adding user-defined operators Expressions Foreign Keys Traversing foreign keys Joining tables Implementing bookings, using a subquery The “Produce a list of costly bookings” exercise contained some messy logic: we had to calculate the booking cost in both the WHERE clause and the CASE statement. Try to simplify happens in its own transaction. That is going to be really slow! 2. There is a decent amount of Python logic getting in your way, and each InsertQuery must be generated and parsed into SQL. 3. That’s a lot

namedtuples Returning Clause Common Table Expressions Foreign Keys and Joins Query operators Three valued logic Adding user-defined operators Expressions SQL Functions SQL Helper Security and SQL Injection Relationships happens in its own transaction. That is going to be really slow! 2. There is a decent amount of Python logic getting in your way, and each InsertQuery must be generated and parsed into SQL. 3. That’s a lot to retrieve the matching row. Failing that, a new row will be created. For “create or get” type logic, typically one would rely on a unique constraint or primary key to prevent the creation of duplicate

happens in its own transaction. That is going to be really slow! 2. There is a decent amount of Python logic getting in your way, and each InsertQuery must be generated and parsed into SQL. 3. That’s a lot to retrieve the matching row. Failing that, a new row will be created. For “create or get” type logic, typically one would rely on a unique constraint or primary key to prevent the creation of duplicate call .get(). return User.get(User.username == username) You can easily encapsulate this type of logic as a classmethod on your own Model classes. The above example first attempts at creation, then falls

bookings, using a subquery The “Produce a list of costly bookings” exercise contained some messy logic: we had to calculate the booking cost in both the WHERE clause and the CASE statement. Try to simplify happens in its own transaction. That is going to be really slow! 2. There is a decent amount of Python logic getting in your way, and each InsertQuery must be generated and parsed into SQL. 3. That’s a lot to retrieve the matching row. Failing that, a new row will be created. For “create or get” type logic, typically one would rely on a unique constraint or primary key to prevent the creation of duplicate

bookings, using a subquery The “Produce a list of costly bookings” exercise contained some messy logic: we had to calculate the booking cost in both the WHERE clause and the CASE statement. Try to simplify happens in its own transaction. That is going to be really slow! 2. There is a decent amount of Python logic getting in your way, and each InsertQuery must be generated and parsed into SQL. 3. That’s a lot to retrieve the matching row. Failing that, a new row will be created. For “create or get” type logic, typically one would rely on a unique constraint or primary key to prevent the creation of duplicate