SQLite Clauses/Conditions: OR

The OR clause in SQLite is used to combine multiple conditions in a query and return results that meet any of the specified conditions. This allows you to filter large datasets and retrieve only the data that meets specific criteria.

Syntax

The basic syntax of the OR clause in SQLite is as follows:

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

Example

Suppose we want to retrieve the details of all the students who scored above 80 in either math or science. We could use the OR clause in SQLite to combine two conditions as follows:

SELECT * FROM students 
WHERE math_score > 80 OR science_score > 80;

Output

The output of the above query would be a list of all the students who scored above 80 in either math or science:

| id | first_name | last_name | math_score | science_score |
|----|------------|-----------|------------|---------------|
|  1 |     John   |     Doe   |         85 |            90 |
|  2 |     Jane  |    Smith  |         90 |            85 |
|  3 |     Bob    |   Johnson |         75 |            90 |
|  4 |     Alice   |   Williams|         80 |            85 |

Explanation

In the example above, we use the WHERE clause to set the conditions of the query. We want to retrieve the details of all the students who scored above 80 in either math or science.

We combine two conditions using the OR clause. The first condition retrieves all the students who scored above 80 in math, and the second condition retrieves all the students who scored above 80 in science.

The query returns all students who meet either of the conditions and displays their details.

Use

The OR clause in SQLite is used to combine multiple conditions in a query and return results that meet any of the specified conditions. It's useful in situations where you need to retrieve data that meets a specific set of criteria and filter large datasets.

Important Points

• The OR clause can combine any number of conditions in a query.
• Use parentheses to group conditions and set their order of precedence.
• Be careful when using the OR clause with multiple conditions as it can become hard to read and understand the query.
• Always use the WHERE clause when filtering data to avoid filtering large datasets in memory.

Summary

In this tutorial, we learned about the OR clause in SQLite and how to use it to combine multiple conditions in a query and retrieve data that meets any of the specified conditions. We saw an example of combining two conditions to retrieve the details of students who scored above 80 in either math or science. It's important to use parentheses to group conditions and always use the WHERE clause to filter data and avoid filtering large datasets in memory.