Comparison Operators

Question:

Start Quiz:

#
# Find all the llamas born between January 1, 1995 and December 31, 1998.
# Fill in the 'where' clause in this query.

QUERY = '''
select name from animals where ...
'''

User's Answer:

(Note: The answer done by the user is not guaranteed to be correct)

query.py

#
# Find all the llamas born between January 1, 1995 and December 31, 1998.
# Fill in the 'where' clause in this query.

QUERY = '''
select name from animals where species = 'llama' and birthdate > '1995-1-1' and birthdate < '1998-12-31'
'''

Solution:

INSTRUCTOR NOTE:

The big difference between comparison operators in SQL and in Python is that we use = for equality in SQL, whereas Python uses ==.

The columns in the animals table are name (a text string), species (also a text string), and birthdate (a date).

Reminder: Dates in our databases will always be in the international standard format, e.g. '1999-12-31'. Make sure to put single quotes around dates.

The comparison operators in SQL are almost the same as the ones in Python: < for less than, > for greater than, != for not equal, <= for less than or equal, and so forth.
One difference is that SQL uses = instead of == to represent equality. You can apply all the basic comparison operators to strings, numbers, dates, and other values.
As a preview, here's the SQL command used to initially create this table:

create table animals (
    name text,
    species text,
    birthdate date
);

a

The columns in the animals table are name (a text string), species (also a text string), and birthdate (a date).

Reminder: Dates in our databases will always be in the international standard format, e.g. '1999-12-31'. Make sure to put single quotes around dates.

As a preview, here's the SQL command used to initially create this table:

create table animals (
    name text,
    species text,
    birthdate date
);