How to get distinct values for non-key column fields in Laravel?
Stefan Izdrail
Founder & Senior Architect · 2026-06-29
Title: Efficiently Handling Distinct Values for Non-Key Columns in Laravel Queries
Introduction:
When working with Laravel applications, you might encounter a situation where you need to fetch rows from a table containing repeated values in one or more non-key column fields. In such cases, understanding the SQL query constructs and how they map to Laravel's Query Builder or Eloquent can be crucial. Today, we will explore different techniques to get distinct values for non-key columns using both methods efficiently.
1. Using Laravel Query Builder:
In this method, you can make use of the Laravel Query Builder for executing custom SQL queries. Here's how you would fetch distinct values for a particular column from a table:
a) By using 'SELECT DISTINCT' statement:
```php
// Retrieve rows with distinct values for "column_name"
$distinctValues = DB::table('table_name')->select(DB::raw('DISTINCT column_name'))->get();
```
In this example, the query will execute a 'SELECT DISTINCT' statement to fetch rows with distinct values for the specified column. The results are stored in an array of objects, each representing a unique row with its associated columns and values.
b) By rewriting the SQL query using Laravel Query Builder:
You can also write your own customized SQL query within Laravel's Query Builder. In the following example, we will fetch distinct values for all non-key columns and store them as an array of objects:
```php
$distinctValues = DB::table('table_name')
->select(DB::raw('DISTINCT column1, DISTINCT column2, ...')) // Specify the columns to fetch distinct values for each
->get();
```
In this case, you would need to specify every column name with the 'distinct' function to ensure that only unique values are fetched. Please note that this approach might be more complex if there are numerous non-key columns.
2. Using Laravel Eloquent:
Eloquent is an ORM, Object Relational Mapper, which makes database interaction a breeze by providing a straightforward API for accessing and manipulating data stored within the database. It also facilitates the execution of custom SQL queries via the Query Builder. To retrieve distinct values for non-key columns using Eloquent:
a) By writing custom SQL query in Eloquent:
You can write your SQL query as a closure and pass it to the 'select' method, ensuring the distinct condition is applied on the specified columns. This approach might be more flexible if you need to fetch data from multiple tables or perform complex operations that are not directly available through the Laravel Query Builder.
```php
// Write your custom SQL query with distinct conditions
$distinctValues = DB::table('table_name')->select(function ($query) {
$query->from('table_name')
->select(DB::raw('DISTINCT column1, DISTINCT column2, ...')) // Specify the columns to fetch distinct values for each
->get();
})->get()->toArray();
```
In this example, we pass our custom SQL query as a closure inside the select method. The result is stored in an array of Eloquent models that you can iterate over.
b) Using Laravel's Collection with 'Collect::unique()':
If you want to retrieve distinct values for all non-key columns, you could consider using Laravel's Collection methods instead. Retrieving the data from your table and converting it into a collection provides some additional flexibility:
```php
$tableData = TableName::all();
// Create a collection with distinct values for each column
$distinctValues = $tableData->map(function ($row) {
return [
'column1' => collect($row)->unique()->values()->toArray(),
'column2' => collect($row)->unique()->values()->toArray(),
// ...
];
})->collapse();
```
In this example, we first fetch all the table data and convert it into a collection. Then, using the map method and an anonymous function, we extract the distinct values for all non-key columns and store them as arrays in the object. Finally, we collapse the nested array to get one flat list of objects representing our results.
Conclusion:
In this blog post, we explored different methods to fetch precise data from tables with repeated values in non-key fields using Laravel's Query Builder or Eloquent. Depending on your requirement, you can choose the appropriate approach among these techniques for retrieving distinct values and ensuring efficient performance of your Laravel application.