How to design Database

A relational database cannot store multiple values in a single field. You will have to create a separate record/table and relate them.

Before starting to build that in Appian, I suggest to look for some training material in the internet.

When asked your question, ChatGPT told me this:

Certainly! To store data in an array format in a database, you have a few options depending on the type of database you are using. Below are some common approaches for different types of databases:

### 1. **Relational Databases (e.g., MySQL, PostgreSQL)**

In relational databases, you typically don't store arrays directly. Instead, you can use one of the following methods:

- **JSON Data Type**: Many modern relational databases support a JSON data type, which allows you to store arrays as JSON.

**Example (PostgreSQL)**:
```sql
CREATE TABLE your_table (
id SERIAL PRIMARY KEY,
data JSONB
);

INSERT INTO your_table (data) VALUES ('[1, 2, 3, 4]');
```

**Example (MySQL)**:
```sql
CREATE TABLE your_table (
id INT AUTO_INCREMENT PRIMARY KEY,
data JSON
);

INSERT INTO your_table (data) VALUES ('[1, 2, 3, 4]');
```

- **Separate Table**: Create a separate table to store the array elements, with a foreign key relationship to the main table.

**Example**:
```sql
CREATE TABLE your_table (
id SERIAL PRIMARY KEY
);

CREATE TABLE your_array_table (
id SERIAL PRIMARY KEY,
your_table_id INT,
value INT,
FOREIGN KEY (your_table_id) REFERENCES your_table(id)
);
```

### 2. **NoSQL Databases (e.g., MongoDB)**

NoSQL databases like MongoDB are designed to handle unstructured data, including arrays, natively.

**Example**:
```javascript
db.your_collection.insertOne({
data: [1, 2, 3, 4]
});
```

### 3. **Using an Array Data Type (PostgreSQL)**

If you are using PostgreSQL, you can also use the built-in array data type.

**Example**:
```sql
CREATE TABLE your_table (
id SERIAL PRIMARY KEY,
data INT[]
);

INSERT INTO your_table (data) VALUES (ARRAY[1, 2, 3, 4]);
```

### 4. **Using a Text Field (as a last resort)**

If your database does not support JSON or array types, you can store the array as a delimited string (e.g., comma-separated values) in a text field. However, this approach is less efficient and more complex to query.

**Example**:
```sql
CREATE TABLE your_table (
id SERIAL PRIMARY KEY,
data TEXT
);

INSERT INTO your_table (data) VALUES ('1,2,3,4');
```

### Conclusion

Choose the method that best fits your use case and the capabilities of your database. If you are using a relational database, the JSON data type or a separate table is often the best approach. If you are using a NoSQL database, you can store arrays directly.