Find missing values with IS NULL. Learn the syntax using an editable sql example.
When to use it
Use this technique in reports, dashboards and database-backed applications. Check the input types, any required imports, and whether the operation changes existing values or produces a new result.
Syntax
SELECT name FROM users WHERE phone IS NULL;
Parameters
Inspect the literals, variables and function arguments used in the example. Replace values with compatible sql types before testing.
Returns / effect
Expected demonstration result: Users with no phone value.
Demo tables (SQLite)
users(id, name, score, active, phone) orders(id, user_id, total, status) products(id, name, price)
This is an isolated temporary SQLite database. Any edits disappear after each run. It is not connected to WordPress.
Expected output
Users with no phone value
Common mistake and fix
Review table and column names and test against sample data; never run unreviewed writes on live data.
Good practices
Keep the example small, check its documented output, then adapt it to your own project with validation and error handling.
Practice exercise
Try changing one input in the find missing values with is null example. Predict how the output changes, then compare with the reference output.
Compatibility: Confirm support in your installed language/runtime version; some examples need modern standard libraries.
Related concepts: sql, examples, syntax
Explain this code
Try a small exercise
Try changing one input in the find missing values with is null example. Predict how the output changes, then compare with the reference output.
Show a hint
Change a single literal or input first; compare the result before making more edits.
Show example solution
SELECT name FROM users WHERE phone IS NULL;
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Educational examples are not a substitute for a real compiler or version-specific documentation. JavaScript, Python and SQLite demos run in isolated browser contexts when supported; Python and SQL load an online WebAssembly runtime on first use. Other languages receive structural hints, not compiler validation. No visitor code executes on WordPress.