How do I select rows where a column has no value in SQLite?

Use IS NULL for this test:

SELECT id, notes
FROM tasks
WHERE notes IS NULL;

In SQLite, = NULL does not work as a test for a missing value. An ordinary comparison with a NULL operand evaluates to NULL; in a WHERE clause, rows whose condition is false or NULL are excluded. SQLite treats IS NULL specially, so it selects rows whose column value is NULL. [S1]

For example, suppose tasks contains these invented rows:

id | notes
1  | NULL
2  | call
3  | email

The query returns:

id | notes
1  | NULL

The text values call and email do not match IS NULL. This example describes SQLite behavior; it does not establish whether another database engine uses identical syntax or behavior.

With the three example rows, compare these conditions:

SELECT id, notes FROM tasks WHERE notes = NULL;
SELECT id, notes FROM tasks WHERE notes IS NULL;

The first query returns no rows: for the row with notes set to NULL, notes = NULL evaluates to NULL, not true, and the WHERE clause excludes it. For the call and email rows, the comparison also has a NULL operand, so it does not select those rows either. The second query returns only id 1, whose notes value is NULL. [S1]

Replace notes with the name of the column you want to check. Use NULL without quotes: 'NULL' is text, not the SQL null value.

A blank-looking display alone does not tell you whether the stored value is NULL or an empty string. If you want to find either kind of value, use both conditions:

SELECT id, notes
FROM tasks
WHERE notes IS NULL OR notes = '';

That query asks for either a NULL value or an empty string. If you only want SQL NULL values, use WHERE notes IS NULL instead. For illustration, suppose the table also has an empty-string value:

id | notes        | Matches IS NULL? | Matches = ''?
1  | NULL         | Yes              | No
2  | call         | No               | No
3  | email        | No               | No
4  | empty string | No               | Yes

Here, empty string labels the example value; it is not the literal text stored in the cell.

List the columns you want after SELECT, keep the table after FROM, and put the null test in WHERE. For example:

SELECT id, task_name, notes
FROM tasks
WHERE notes IS NULL;

If the result is empty, check that you are using the intended table and column. If values that look blank are actually empty strings, IS NULL will not select them; inspect the values without the filter and choose the condition that matches your goal. SQLite’s null comparison rule explains why = NULL is not the fix, but it does not tell you what values your table contains. [S1]

Reusable pattern:

SELECT columns_you_want
FROM table_name
WHERE column_name IS NULL;

Replace the example identifiers with names from your database.