008 SQL OR

The current W3Schools tutorial page explains the SQL OR Operator:

The OR operator in SQL is used within the WHERE clause to filter records based on multiple conditions, returning records if any condition is true.

Syntax demonstrated:

SELECT column1, column2, ...
FROM table_name
WHERE condition1 OR condition2 OR condition3 ...;

Key differences:
- OR: Returns a record if at least one condition is true.
- AND: Returns a record only if all conditions are true.

Examples Provided:

Selecting all customers from Germany or Spain:

SELECT * FROM Customers WHERE Country = 'Germany' OR Country = 'Spain';

Selecting records where at least one condition (city is 'Berlin', name starts with 'G', or country is 'Norway') is true.

Combining AND and OR:

Parentheses are important to ensure the correct logic.
Without parentheses:
```
SELECT * FROM Customers
WHERE Country = 'Spain' AND CustomerName LIKE 'G%' OR CustomerName LIKE 'R%';
```
This query returns all customers from Spain whose names start with 'G', plus all customers (from any country) whose names start with 'R'.

With parentheses:

SELECT * FROM Customers
WHERE Country = 'Spain' AND (CustomerName LIKE 'G%' OR CustomerName LIKE 'R%');

This will correctly return only customers from Spain whose names start with 'G' or 'R'.

Tip: Parentheses in complex conditions are critical for correct filtering logic.[1]

SQL OR Operator

The SQL OR Operator

The WHERE clause can contain one or more OR operators.

The OR operator is used to filter records based on more than one condition, like if you want to return all customers from Germany but also those from Spain:

Select all customers from Germany or Spain:

SELECT *  
FROM Customers  
WHERE Country = 'Germany' OR Country = 'Spain';

Syntax

SELECT column1, column2, ...
FROM table_name
WHERE condition1 OR condition2 OR condition3 ...;

OR vs AND

The OR operator displays a record if any of the conditions are TRUE.

The AND operator displays a record if all the conditions are TRUE.

Demo Database

Below is a selection from the Customers table used in the examples:

CustomerID	CustomerName	ContactName	Address	City	PostalCode	Country
1	Alfreds Futterkiste	Maria Anders	Obere Str. 57	Berlin	12209	Germany
2	Ana Trujillo Emparedados y helados	Ana Trujillo	Avda. de la Constitución 2222	México D.F.	05021	Mexico
3	Antonio Moreno Taquería	Antonio Moreno	Mataderos 2312	México D.F.	05023	Mexico
4	Around the Horn	Thomas Hardy	120 Hanover Sq.	London	WA1 1DP	UK
5	Berglunds snabbköp	Christina Berglund	Berguvsvägen 8	Luleå	S-958 22	Sweden

At Least One Condition Must Be True

The following SQL statement selects all fields from Customers where either City is "Berlin", CustomerName starts with the letter "G" or Country is "Norway":

SELECT * FROM Customers  
WHERE City = 'Berlin' OR CustomerName LIKE 'G%' OR Country = 'Norway';

Combining AND and OR

You can combine the AND and OR operators.

The following SQL statement selects all customers from Spain that starts with a "G" or an "R".

Make sure you use parenthesis to get the correct result.

Select all Spanish customers that starts with either "G" or "R":

SELECT * FROM Customers
WHERE Country = 'Spain' AND (CustomerName LIKE 'G%' OR CustomerName LIKE 'R%');

Without parenthesis, the select statement will return all customers from Spain that starts with a "G", plus all customers that starts with an "R", regardless of the country value:

Select all customers that either:
are from Spain and starts with either "G", or
starts with the letter "R":

SELECT * FROM Customers
WHERE Country = 'Spain' AND CustomerName LIKE 'G%' OR CustomerName LIKE 'R%';