码农教程 - 一技在手,衣食无忧! tools

目录

SQL OR Operator

❮ Previous Next ❯

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:

Example

Select all customers from Germany or Spain:

SELECT *
FROM Customers
WHERE Country = 'Germany' OR Country = 'Spain';
Try it Yourself »

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":

Example

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

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.

Example

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%');
Try it Yourself »

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:

Example

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%';
Try it Yourself »

Test Yourself With Exercises

Exercise:

Select all records where the City column has the value 'Berlin' or 'London'.

 * FROM Customers
 City = 'Berlin'
  = '';

Start the Exercise


❮ Previous Next ❯