About the Tutorial SQLAlchemy is a popular SQL toolkit and Object Relational Mapper. It is written in Python and gives full power and flexibility of SQL to an application developer. It is an open source understanding of the Python programming language. A basic understanding of relational databases, DB- API, and SQL is desired to understand this tutorial. Copyright & Disclaimer  Copyright 2018 by Tutorials Point ........................................................................ 7 5. SQLAlchemy Core – SQL Expressions ......................................................................................

Query operators Three valued logic Adding user-defined operators Expressions SQL Functions SQL Helper Security and SQL Injection API Documentation Database Query-builder Fields Schema Manager Model every Person returned by the original SELECT! We can avoid this by performing a JOIN and using a SQL function to aggregate the results. query = (Person .select(Person, fn.COUNT(Pet.id).alias('pet_count')) prints: # Bob # * Kitty # * Fido # Grandma L. # Herb # * Mittens Jr SQL Functions One last query. This will use a SQL function to find all people whose names start with either an upper or lower-case

for every Person returned by the original SELECT! We can avoid this by performing a JOIN and using a SQL function to aggregate the results. query = (Person .select(Person, fn.COUNT(Pet.id).alias('pet_count')) name) # prints: # Bob # * Kitty # * Fido # Grandma L. # Herb # * Mittens Jr SQL Functions One last query. This will use a SQL function to find all people whose names start with either an upper or lower-case close() This is just the basics! You can make your queries as complex as you like. All the other SQL clauses are available as well, such as: • group_by() • having() • limit() and offset() Check the

records Counting records Aggregating records Retrieving Scalar Values SQL Functions, Subqueries and “Raw expressions” Security and SQL Injection Window functions Retrieving row tuples / dictionaries / namedtuples every Person returned by the original SELECT! We can avoid this by performing a JOIN and using a SQL function to aggregate the results. query = (Person .select(Person, fn.COUNT(Pet.id).alias('pet_count')) prints: # Bob # * Kitty # * Fido # Grandma L. # Herb # * Mittens Jr SQL Functions One last query. This will use a SQL function to find all people whose names start with either an upper or lower-case

for every Person returned by the original SELECT! We can avoid this by performing a JOIN and using a SQL function to aggregate the results. query = (Person .select(Person, fn.COUNT(Pet.id).alias('pet_count')) name) # prints: # Bob # * Kitty # * Fido # Grandma L. # Herb # * Mittens Jr SQL Functions One last query. This will use a SQL function to find all people whose names start with either an upper or lower-case close() This is just the basics! You can make your queries as complex as you like. All the other SQL clauses are available as well, such as: • group_by() • having() • limit() and offset() Check the

records Counting records Aggregating records Retrieving Scalar Values SQL Functions, Subqueries and “Raw expressions” Security and SQL Injection Window functions Retrieving row tuples / dictionaries / namedtuples every Person returned by the original SELECT! We can avoid this by performing a JOIN and using a SQL function to aggregate the results. query = (Person .select(Person, fn.COUNT(Pet.id).alias('pet_count')) prints: # Bob # * Kitty # * Fido # Grandma L. # Herb # * Mittens Jr SQL Functions One last query. This will use a SQL function to find all people whose names start with either an upper or lower-case

for every Person returned by the original SELECT! We can avoid this by performing a JOIN and using a SQL function to aggregate the results. query = (Person .select(Person, fn.COUNT(Pet.id).alias('pet_count')) name) # prints: # Bob # * Kitty # * Fido # Grandma L. # Herb # * Mittens Jr SQL Functions One last query. This will use a SQL function to find all people whose names start with either an upper or lower-case close() This is just the basics! You can make your queries as complex as you like. All the other SQL clauses are available as well, such as: • group_by() • having() • limit() and offset() Check the

Query operators Three valued logic Adding user-defined operators Expressions SQL Functions SQL Helper Security and SQL Injection Relationships and Joins Model definitions Performing simple joins Joining for every Person returned by the original SELECT! We can avoid this by performing a JOIN and using a SQL function to aggregate the results. query = (Person .select(Person, fn.COUNT(Pet.id).alias('pet_count')) prints: # Bob # * Kitty # * Fido # Grandma L. # Herb # * Mittens Jr SQL Functions One last query. This will use a SQL function to find all people whose names start with either an upper or lower-case

for every Person returned by the original SELECT! We can avoid this by performing a JOIN and using a SQL function to aggregate the results. query = (Person .select(Person, fn.COUNT(Pet.id).alias('pet_count')) name) # prints: # Bob # * Kitty # * Fido # Grandma L. # Herb # * Mittens Jr SQL Functions One last query. This will use a SQL function to find all people whose names start with either an upper or lower-case for instructions on installing peewee. Every model has a create_table() classmethod which runs a SQL CREATE TABLE statement in the database. This method will create the table, including all columns, foreign-key

records Counting records Aggregating records Retrieving Scalar Values SQL Functions, Subqueries and “Raw expressions” Security and SQL Injection Window functions Retrieving row tuples / dictionaries / namedtuples every Person returned by the original SELECT! We can avoid this by performing a JOIN and using a SQL function to aggregate the results. query = (Person .select(Person, fn.COUNT(Pet.id).alias('pet_count')) prints: # Bob # * Kitty # * Fido # Grandma L. # Herb # * Mittens Jr SQL Functions One last query. This will use a SQL function to find all people whose names start with either an upper or lower-case