How to Retrieve Distinct Values from Multiple Columns in MySQL?

Distinct Values from Multiple Columns in MySQL

In database management systems, it is often necessary to retrieve unique combinations of data from multiple columns. However, merely using the DISTINCT keyword may result in unwanted repetitions due to the asymmetrical arrangement of values.

To address this issue, consider employing the GROUP BY clause. This approach groups rows by the specified columns and returns only one row for each unique combination. For instance, the following query accomplishes this objective:

<code class="sql">SELECT foo, bar
FROM my_table
GROUP BY foo, bar;</code>

The GROUP BY clause aggregates rows with identical values in both the foo and bar columns, ensuring that only distinct pairs are included in the resultSet. By utilizing this technique, you can effectively eliminate duplicate combinations and extract the unique values you require from your database.

The above is the detailed content of How to Retrieve Distinct Values from Multiple Columns in MySQL?. For more information, please follow other related articles on the PHP Chinese website!