Listing Entities

Retrieving data is a fundamental operation in any database system. With Onyx Database, you can efficiently list entities using simple methods. This tutorial demonstrates how to retrieve a list of entities.

Steps to List Entities (Onyx Cloud Database)

1

Declare the Schema

Use the provided JSON schema to define your entity in the Onyx Cloud Database.
1{
2  "tables": [
3    {
4      "name": "Player",
5      "identifier": {
6        "name": "id",
7        "type": "Long",
8        "generator": "Sequence"
9      },
10      "attributes": [
11        {
12          "name": "firstName",
13          "type": "String"
14        },
15        {
16          "name": "lastName",
17          "type": "String"
18        }
19      ],
20      "relationships": [],
21      "indexes": []
22    }
23  ],
24  "revisionDescription": "Initial schema for Player entity"
25}
2

List the Entities

Use the list method to retrieve all instances of the entity.
1const players = await db.from('Player').list();
3

Print the Retrieved Entities

Iterate over the list of entities and perform operations as needed.
1for (const player of players) {
2    console.log(`${player.lastName}, ${player.firstName}`);
3}
Next Tutorial: Querying Entities

Important Notes

  • The list method retrieves all entities of the specified type if no criteria are provided.
  • For large datasets, consider using pagination or adding query criteria to limit the results.

Troubleshooting

  • No Entities Returned: Ensure that entities of the specified type exist in the database.
  • Class Not Found: Verify that the entity class is correctly defined and available in the classpath.
  • Performance Issues: Use query criteria or pagination to improve performance when dealing with large datasets.

Next Steps

Now that you know how to list entities, you can explore more advanced querying techniques: