Conteúdo do Curso
Databases in Python
Databases in Python
Reading from DB
This chapter focuses solely on retrieving records from a database using SQLAlchemy. You’ll learn how to fetch single or multiple records efficiently using various querying methods.
Fetching a Single Record
To retrieve a single record, use query()
and apply filters. For instance, to find a product by its name:
Here, .filter(Product.name == "Laptop")
selects products with the name "Laptop," and .first()
returns the first matching record or None
.
Fetching Multiple Records
To retrieve multiple records, combine filter()
with .all()
. For example, to list all products:
To filter products, e.g., those priced above $1000, modify the query:
Using get() for Primary Key Lookups
For efficient retrieval by primary key, use get()
. For example, fetching a product with ID 1:
Limiting Results
To limit the number of records retrieved, apply .limit()
. For example, to fetch the first 3 products:
By mastering these techniques, you’ll efficiently retrieve the data you need, whether it’s a single record, multiple filtered results, or a limited subset.
Tarefa
Complete the given code to retrieve all records from the products
table in the database. Use the session
object, the Product
model, and the appropriate method to fetch all entries.
Obrigado pelo seu feedback!
Reading from DB
This chapter focuses solely on retrieving records from a database using SQLAlchemy. You’ll learn how to fetch single or multiple records efficiently using various querying methods.
Fetching a Single Record
To retrieve a single record, use query()
and apply filters. For instance, to find a product by its name:
Here, .filter(Product.name == "Laptop")
selects products with the name "Laptop," and .first()
returns the first matching record or None
.
Fetching Multiple Records
To retrieve multiple records, combine filter()
with .all()
. For example, to list all products:
To filter products, e.g., those priced above $1000, modify the query:
Using get() for Primary Key Lookups
For efficient retrieval by primary key, use get()
. For example, fetching a product with ID 1:
Limiting Results
To limit the number of records retrieved, apply .limit()
. For example, to fetch the first 3 products:
By mastering these techniques, you’ll efficiently retrieve the data you need, whether it’s a single record, multiple filtered results, or a limited subset.
Tarefa
Complete the given code to retrieve all records from the products
table in the database. Use the session
object, the Product
model, and the appropriate method to fetch all entries.
Obrigado pelo seu feedback!
Reading from DB
This chapter focuses solely on retrieving records from a database using SQLAlchemy. You’ll learn how to fetch single or multiple records efficiently using various querying methods.
Fetching a Single Record
To retrieve a single record, use query()
and apply filters. For instance, to find a product by its name:
Here, .filter(Product.name == "Laptop")
selects products with the name "Laptop," and .first()
returns the first matching record or None
.
Fetching Multiple Records
To retrieve multiple records, combine filter()
with .all()
. For example, to list all products:
To filter products, e.g., those priced above $1000, modify the query:
Using get() for Primary Key Lookups
For efficient retrieval by primary key, use get()
. For example, fetching a product with ID 1:
Limiting Results
To limit the number of records retrieved, apply .limit()
. For example, to fetch the first 3 products:
By mastering these techniques, you’ll efficiently retrieve the data you need, whether it’s a single record, multiple filtered results, or a limited subset.
Tarefa
Complete the given code to retrieve all records from the products
table in the database. Use the session
object, the Product
model, and the appropriate method to fetch all entries.
Obrigado pelo seu feedback!
This chapter focuses solely on retrieving records from a database using SQLAlchemy. You’ll learn how to fetch single or multiple records efficiently using various querying methods.
Fetching a Single Record
To retrieve a single record, use query()
and apply filters. For instance, to find a product by its name:
Here, .filter(Product.name == "Laptop")
selects products with the name "Laptop," and .first()
returns the first matching record or None
.
Fetching Multiple Records
To retrieve multiple records, combine filter()
with .all()
. For example, to list all products:
To filter products, e.g., those priced above $1000, modify the query:
Using get() for Primary Key Lookups
For efficient retrieval by primary key, use get()
. For example, fetching a product with ID 1:
Limiting Results
To limit the number of records retrieved, apply .limit()
. For example, to fetch the first 3 products:
By mastering these techniques, you’ll efficiently retrieve the data you need, whether it’s a single record, multiple filtered results, or a limited subset.
Tarefa
Complete the given code to retrieve all records from the products
table in the database. Use the session
object, the Product
model, and the appropriate method to fetch all entries.