PostgreSQL Comparison Operators

SELECT *
FROM empls
WHERE first_name = 'Frog';

In this example, the SELECT statement above returns all rows from the employee table, where first_name equals Frog.

Example – operator <>

There are two ways to check inequality in PostgreSQL. You can use the <> or != operator.
For example, we can check for inequality using the <> operator in the following way :

In this example, the SELECT operator above returns all rows from the employee table, where first_name equals Frog.

An example is the <> operator

There are two ways to check inequality in PostgreSQL. You can use the <> or != operator.
For example, we can check for inequality using the <> operator in the following way :

SELECT *
FROM empls
WHERE first_name <> 'Frog';

In this example, the SELECT statement returns all rows from the employee table where first_name does not equally Frog.

Or you can also write this query using the != operator as shown below :

SELECT *
FROM empls
WHERE first_name != 'Frog';

Both these requests will return the same results.

Example – operator >

You can use the > operator in PostgreSQL to check the expression for more than that.

SELECT *
FROM products
WHERE product_id > 50;

In this example, the SELECT operator will return all rows from the products table where product_id is over 50. a product_id equal to 50 will not be included in the result set.

Example – the >= operator

In PostgreSQL, you can use the >= operator to check whether the expression is larger or equal.

SELECT *
FROM products
WHERE product_id >= 50;

In this example, the SELECT operator will return all rows from the products table where product_id is greater than or equal to 50. In this case, a product_id equal to 50 will be included in the result set.

The example is the operator <

You can use the < statement in PostgreSQL to check the expressionless.

SELECT *
FROM inventory
WHERE inventory_id < 25;

In this example, the SELECT operator will return all rows from the inventory table where inventory_id is less than 25. An inventory_id value of 25 will not be included in the result set.

Example – operator <=

In PostgreSQL, you can use the <= operator to test an expression that is less than or equal.

SELECT *
FROM inventory
WHERE inventory_id <= 25;

In this example, the SELECT operator will return all rows from the inventory table where inventory_id is less than or equal to 25. In this case, n inventory_id value 25 will be included in the result set.

PostgreSQL: Comparison Operators | Course