A field lookup is essentially a way to specify how Django should filter query results based on a model field's value.

Basic Structure

A field lookup takes the form field__lookuptype=value. Here, field is the name of the model field, lookuptype is the type of comparison, and value is the value to compare against.

Common Field Lookups

• exact - the default lookup type; it performs case-sensitive comparisons.
  (SELECT * FROM Book WHERE genre = 'philosophy';)

• iexact - case-insensitive match.
  (SELECT * FROM Author WHERE LOWER(pen_name) = LOWER('george orwell');)

• contains - case-sensitive containment test.
  (SELECT * FROM Book WHERE title LIKE '%House%';)

• icontains - case-insensitive containment test.
  (SELECT * FROM Book WHERE LOWER(title) LIKE LOWER('%house%');)

• in - in a given iterable; often used for filtering by a list of values.
  (SELECT * FROM Author WHERE id IN (1, 4, 7);)

• gt, gte, lt, lte - greater than, greater than or equal to, less than, and less than or equal to.
  (SELECT * FROM Author WHERE id < 10;)

• startswith, istartswith - string starts with a value (case-sensitive and insensitive versions).
  (SELECT * FROM Author WHERE first_name LIKE 'J%';)

• endswith, iendswith - string ends with a value (case-sensitive and insensitive versions).
  (SELECT * FROM Author WHERE last_name LIKE '%e';)

• range - within a certain range (inclusive).
  (SELECT * FROM Book WHERE id BETWEEN 1 AND 5;)

• date, year, month, day - specific date components.
  (SELECT * FROM Book WHERE EXTRACT(YEAR FROM pub_date) = 2023;)