# Filtering III — Special Comparison Operators 5 of 8 · Comparing with Missing Values

The instruction on this exercise is not clear
What am I supposed to do?

### Learn

Let’s display some of the columns in `employee`.

employee_id last_name first_name title reports_to
2 Edwards Nancy Sales Manager 1
3 Peacock Jane Sales Support Agent 2
4 Park Margaret Sales Support Agent 2
5 Johnson Steve Sales Support Agent 2
6 Mitchell Michael IT Manager 1
7 King Robert IT Staff 6
8 Callahan Laura IT Staff 6

Before looking at the results, try to determine the result of the following query.

SELECT employee_id, last_name, first_name, title, reports_to

FROM employee

WHERE reports_to <> 1;

Copy

Have you thought about it? How many rows are there in the result? Let’s see . . .

employee_id last_name first_name title reports_to
3 Peacock Jane Sales Support Agent 2
4 Park Margaret Sales Support Agent 2
5 Johnson Steve Sales Support Agent 2
7 King Robert IT Staff 6
8 Callahan Laura IT Staff 6

We got five rows! Did it match what you had in mind? What happened to the very first row?

employee_id last_name first_name title reports_to

Shouldn’t a “missing value” be different from `1`?

We’ll learn what’s going on here in the next couple of screens. For now, let’s extrapolate from what we saw above to solve an exercise.

### Instructions

1. Run the following query and observe the results.
``````SELECT customer_id, first_name, last_name, fax
FROM customer
``````

This is the LEARN I’m not sure what they need from this exercise

It seems not all the instructions appeared to you, they should read:

1. Run the following query and observe the results.

``````SELECT customer_id, first_name, last_name, fax
FROM customer;
``````
2. Given that all values in the `fax` column are either missing or start with a `+`, how many rows would the query return if we added the following `WHERE` statement to it?

``````WHERE SUBSTRING(fax, 1, 1) <> '+';
``````
3. To answer the question, write `SELECT <answer>;` replacing `<answer>` with the number of rows you think the query will return. For example, if you think that the query returns `2` rows, write `SELECT 2;`.

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Okay, thank you very much

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