PostgreSQL condition OR

Preamble

PostgreSQL condition OR is used to check two or more conditions under which records are returned when any of these conditions are met. It can be used in SELECT, INSERT, UPDATE, or DELETE statements.

The syntax for OR condition in PostgreSQL

WHERE condition1
OR condition2
…
OR condition_n;

Parameters and arguments of the condition

• condition1, condition2, condition_n are any conditions that must be met to select records.

Note:

• PostgreSQL condition OR allows checking 2 or more conditions.
• PostgreSQL condition OR requires that any condition (i.e.: condition1, condition2, condition_n) is met to include a record in the resulting set.

Example of a condition with the SELECT operator

The first example of the PostgreSQL condition OR that we will look at includes a SELECT operator with two conditions:

SELECT *
FROM products
WHERE product_type = 'Hardware'
OR product_id > 400;

In this PostgreSQL example, the OR condition will return all records from products with product_type equal to ‘Hardware’ or product_id greater than 400. Since the SELECT operator uses *, all fields from the products table will appear in the result set.

Example of a condition with a SELECT operator (3 conditions)

In the following PostgreSQL example OR the SELECT operator with 3 conditions is considered. If any of these conditions are met, the record will be included in the result set.

SELECT product_id,
product_name
FROM products
WHERE product_type = 'Hardware'
OR product_type = 'Software'
OR product_id > 1000;

In this PostgreSQL example, the OR condition will return all product_id and product_name values from the products table, where product_type equals ‘Hardware’ or product_type is ‘Software’ or product_id greater than 1000.

Example condition with the INSERT operator

PostgreSQL condition OR can be used in the INSERT operator.
For example:

INSERT INTO products
(product_id, product_name)
SELECT inventory_id,
product_name
FROM inventory
WHERE quantity > 0
OR product_name = 'Memory';

This example of PostgreSQL OR will insert into the products table all inventory_id and product_name records from the inventory table whose size is greater than 0 or product_name equals ‘Memory’.

Example of a condition with the UPDATE operator

PostgreSQL condition OR can be used in UPDATE expression.
For example:

UPDATE products
SET product_type = 'Hardware'
WHERE product_name = 'Memory'
OR product_name = 'SSD';

In this PostgreSQL example, the OR condition will update all product_type values in the products table to ‘Hardware’, where product_name is ‘Memory’ or product_name is ‘SSD’.

Example of a condition with DELETE operator

PostgreSQL condition OR can be used in DELETE operators.
For example:

DELETE FROM contacts
WHERE last_name = 'Hard'
OR first_name = 'Jack';

In this PostgreSQL example, OR conditions will delete all records from the contacts table that had last_name with ‘Hard’ or first_name with ‘Jack’.

Postgres Conditionals: How to Use Case

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