SQLite: IS NULL Condition
This SQLite tutorial explains how to use the SQLite IS NULL condition with syntax and examples.
Description
The SQLite IS NULL Condition is used to test for a NULL value in a SELECT, INSERT, UPDATE, or DELETE statement.
Syntax
The syntax for the IS NULL Condition in SQLite is:
expression IS NULL
Parameters or Arguments
- expression
- The expression to test whether it is a NULL value.
Note
- If expression is a NULL value, the condition evaluates to TRUE.
- If expression is not a NULL value, the condition evaluates to FALSE.
Example - With SELECT Statement
Let's look at an example of how to use SQLite IS NULL in a SELECT statement:
SELECT * FROM employees WHERE department IS NULL;
This SQLite IS NULL example will return all records from the employees table where the department contains a NULL value.
Example - With INSERT Statement
Next, let's look at an example of how to use SQLite IS NULL in an INSERT statement:
INSERT INTO temp (temp_employee_id, temp_last_name, temp_first_name) SELECT employee_id, last_name, first_name FROM employees WHERE first_name IS NULL;
This SQLite IS NULL example will insert records into the temp table where the first_name contains a NULL value.
Example - With UPDATE Statement
Next, let's look at an example of how to use SQLite IS NULL in an UPDATE statement:
UPDATE employees SET first_name = 'Unknown' WHERE first_name IS NULL;
This SQLite IS NULL example will update records in the employees table and set the first_name to 'Unknown' where the first_name field contains a NULL value.
Example - With DELETE Statement
Next, let's look at an example of how to use SQLite IS NULL in a DELETE statement:
DELETE FROM employees WHERE employee_id IS NULL;
This SQLite IS NULL example will delete all records from the employees table where the employee_id contains a NULL value.
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