Leveraging JSON Columns in Laravel and MySQL

Working with relational databases is efficient in many scenarios, but handling unstructured data can often lead to complexities, especially when trying to maintain a structured schema. Allow me to share my experience from a recent project involving a Hospital ERP system, specifically the development of a Medical Record module. In this module, the challenge lay in efficiently storing vast amounts of diverse medical data for each patient.

Traditionally, such requirements would necessitate the creation of numerous relational tables, potentially resulting in a cumbersome and convoluted database schema. To illustrate, for each medical record, I estimated the need for around 10 tables. This included tables for storing medication history, investigations, prescriptions, advice, diagnoses, complaints, and personal habits, among others. Consequently, managing this plethora of tables would have been arduous and inefficient.

Fortunately, MySQL’s JSON data type came to the rescue. Leveraging this feature, I realized I could consolidate the disparate medical data into a single table without compromising on data integrity or performance. However, I encountered a challenge when attempting to seamlessly append new data to the JSON column without resorting to cumbersome workarounds.

Unlike typical NoSQL databases where appending data to a collection is straightforward, MySQL’s JSON handling posed limitations. Many existing solutions involved fetching all existing data, merging arrays, and then updating the JSON column, a process that felt cumbersome and inefficient.

In search of a more elegant solution, I turned to Laravel and devised a custom method to append data directly to the JSON column without the need for fetching and merging existing data. Here’s the method I developed:

public function appendJson(string $field, array $data): void {
        $jsonObject = collect($data)->map(function ($value, $key) {
            return "'$key', '$value'";
        })->implode(', ');
        $this->update([
            $field => DB::raw("CASE WHEN $field IS NULL THEN JSON_ARRAY(JSON_OBJECT($jsonObject)) ELSE JSON_ARRAY_APPEND($field, '$', JSON_OBJECT($jsonObject)) END")
        ]);
    }

Implemented within the model, this method seamlessly integrates into the Laravel workflow. By simply passing the column name and the data array, it appends the new JSON object to the existing JSON array within the specified column, all in a single database operation.

This approach not only streamlines the data management process but also eliminates the need for multiple relational tables, reducing database complexity and maintenance overhead. Now, with just one table, I can efficiently manage and store diverse medical data while maintaining a clean and structured database schema.

In conclusion, the synergy between MySQL’s JSON data type and Laravel’s flexibility has empowered me to overcome the challenges of managing unstructured data, paving the way for more efficient and scalable solutions in Hospital ERP systems and beyond.