SQL comparison operators

SQL comparison operators are used in the WHERE sentence to determine which records to select. Here is a list of comparison statements that you can use in SQL:

Operator of equality

In SQL you can use = operator to check for equality in a query.

In this example, we have a table supplies with the following data:

Enter the following SQL statement:

SELECT *
FROM suppls
WHERE suppl_name = 'Yandex';

1 record will be selected. Here are the results that you should get:

In this example, the SELECT statement above returns all rows from the suppliers table where supplier_name is Yandex.

Inequality operator

In SQL there are two ways to check for inequality in a query. You can use the <> or != operator. Both will return the same results.

Let’s use the same table as in the previous example.

Execute the following SQL statement to check for inequality using the <> statement:

SELECT *
FROM suppls
WHERE suppl_name <> 'Yandex';

Or enter the following SQL statement to use the != operator:

SELECT *
FROM suppls
WHERE suppl_name != 'Yandex';

8 records will be selected. Here are the results you should get using one of the SQL operators:

In this example, both SELECT statements will return all rows from the suppliers table where supplier_name does not equal Yandex.

Operator is larger than

You can use the > operator in SQL to check an expression for more than one.

In this example, we have a table with the following data:

In this example, we have a table of customers with the following data:

Enter the following SQL statement:

SELECT *
FROM customs
WHERE custom_id > 6000;

Three entries will be selected. Here are the results that you will get:

In this example, the SELECT operator returns all rows from the customer table where customer_id is greater than 6000. Records with customer_id equal to or less than 6000 will not be included in the result set.

The operator is greater than or equal to

In SQL you can use the >= operator to check the expression for more or equal.

Let’s use the same table as in the previous example.

Enter the following SQL statement:

SELECT *
FROM customs
WHERE custom_id >= 6000;

Four entries will be selected. Here are the results that you should get:

In this example, the SELECT operator will return all rows from the customer_id table where customer_id is greater than or equal to 6000. In this case, the value of supplier_id equal to 6000 will be included in the result set.

The operator is less than

You can use the < in SQL statement to check the expression less than.

In this example, we have a product table with the following data:

Enter the following SQL statement:

SELECT *
FROM prods
WHERE prod_id < 5;

4 entries will be selected. Here are the results you should get:

In this example, the SELECT operator returns all rows from the products table where prod_id is less than 5. a prod_id equal to 5 will not be included in the result set.

The operator is less than or equal to

In SQL you can use the <= operator to check an expression that is less than or equal.

Let’s use the same table of products as in the previous example.

Enter the following SQL statement:

SELECT *
FROM prods
WHERE prod_id <= 5;

5 records will be selected. Here are the results you should get:

In this example, the SELECT operator returns all rows from the products table where prod_id is less than or equal to 5. In this case, prod_id equal to 5 will be included in the result set.

Understanding Set Comparison Operator in SQL