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Filter data selected from a Table - Simple

Having connected to the database, it's now time to practice filtering your queries!

As mentioned in the video, a where() clause is used to filter the data that a statement returns. For example, to select all the records from the census table where the sex is Female (or 'F') we would do the following:

select([census]).where(census.columns.sex == 'F')

In addition to == we can use basically any python comparison operator (such as <=, !=, etc) in the where() clause.

This exercise is part of the course

Introduction to Databases in Python

View Course

Exercise instructions

  • Select all records from the census table by passing in census as a list to select().
  • Append a where clause to stmt to return only the records with a state of 'New York'.
  • Execute the statement stmt using .execute() on connection and retrieve the results using .fetchall().
  • Iterate over results and print the age, sex and pop2000 columns from each record. For example, you can print out the age of result with result.age.

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

# Create a select query: stmt
stmt = ____

# Add a where clause to filter the results to only those for New York : stmt_filtered
stmt = stmt.____

# Execute the query to retrieve all the data returned: results
results = ____

# Loop over the results and print the age, sex, and pop2000
for ___ in ____:
    print(result.age, ____, ____)
Edit and Run Code