REST-Jdbc — JSONPlaceholder

JSONPlaceholder is a public test API without authentication — well suited for trying the RestJdbc driver (read and write).

Quick start with the JDBC client

SQL files can be run directly with the driver JAR:

java -jar /path/to/restjdbc.jar jsonplaceholder.sql

The file jsonplaceholder.sql contains the connection and sample queries. Steps:

1. Obtain the driver JAR (absolute path to restjdbc.jar)
2. Run the command in the folder that contains jsonplaceholder.sql and jsonplaceholder-spec.json

In the JDBC client:

connect 'jdbc:rest:https://jsonplaceholder.typicode.com|spec=jsonplaceholder-spec.json'

The file ends with quit to exit the client.

1. JDBC URL

jdbc:rest:https://jsonplaceholder.typicode.com

The API base URL is set in the JDBC URL.

Part	Value
Driver prefix	jdbc:rest:
API base URL	https://jsonplaceholder.typicode.com
SQL schema	public (default)

Connection example (Java):

Properties props = new Properties();
props.setProperty("spec", "/path/to/jsonplaceholder-spec.json");

Connection conn = DriverManager.getConnection(
    "jdbc:rest:https://jsonplaceholder.typicode.com", props);

2. Connection properties

Property	Value for JSONPlaceholder	Required
spec	Path to spec (see below)	Yes
auth	not needed (none)	No
user, password, token	—	No
keyStore, …	—	No

Minimal:

props.setProperty("spec", "/path/to/jsonplaceholder-spec.json");

Spec path: absolute path to your local copy of the spec file.

Spec file: jsonplaceholder-spec.json

3. Spec file

File: jsonplaceholder-spec.json

Excerpt (posts with page pagination):

{
  "entities": [
    {
      "name": "posts",
      "path": "/posts",
      "pagination": {
        "type": "page",
        "limitParam": "_limit",
        "pageParam": "_page",
        "defaultLimit": 10
      },
      "columns": [
        { "name": "id", "type": "BIGINT", "primaryKey": true },
        { "name": "userId", "type": "BIGINT" },
        { "name": "title", "type": "VARCHAR" },
        { "name": "body", "type": "VARCHAR" }
      ]
    }
  ]
}

Tables (entities)

SQL table	REST path	Pagination
users	/users	none (single request)
posts	/posts	page with _limit, _page
comments	/comments	page with _limit, _page
albums	/albums	none
photos	/photos	page with _limit, _page
todos	/todos	page with _limit, _page

With page pagination the driver automatically fetches all pages (e.g. all 100 posts) until no data remains.

Nested fields on users (address, company) are deliberately omitted in the spec — the driver reads flat top-level fields by default.

4. Authentication

JSONPlaceholder requires no authentication.

props.setProperty("auth", "none");

Or simply omit auth properties.

No Authorization headers are sent; client certificate (clientcert) is not required.

5. SQL examples

Quote mixed-case column names in SQL ("userId").

SELECT

SELECT id, name, email FROM users;

SELECT id, title FROM posts FILTER userId=1;

SELECT id, name, email FROM comments FILTER postId=1;

SELECT id, title, completed FROM todos FILTER userId=1;

SQL	HTTP
SELECT … FROM users	GET https://jsonplaceholder.typicode.com/users
SELECT … FROM posts FILTER userId=1	GET …/posts?userId=1
SELECT … FROM comments FILTER postId=1	GET …/comments?postId=1
SELECT … FROM posts (all posts)	GET …/posts?_limit=10&_page=1, then _page=2, …

FILTER forwards filters to the API server-side (unlike local WHERE).

INSERT

INSERT INTO posts ("userId", title, body)
VALUES (1, 'Test', 'Body');

→ POST https://jsonplaceholder.typicode.com/posts with JSON body {"userId":1,"title":"Test","body":"Body"}.

JSONPlaceholder simulates write operations — the API responds successfully but does not persist data.

UPDATE

UPDATE posts SET title = 'New title', body = 'New content' FILTER id=1;

→ PUT https://jsonplaceholder.typicode.com/posts/1 with JSON body from SET columns.

DELETE

DELETE FROM posts FILTER id=1;

→ DELETE https://jsonplaceholder.typicode.com/posts/1.

6. System tables

Query metadata from the spec:

SELECT table_name, remarks FROM system.table_list;

SELECT column_name, type_name FROM system.column_list WHERE table_name = 'posts';

SELECT column_name FROM system.pk_list WHERE table_name = 'posts';

7. Notes

• Writing: INSERT/UPDATE/DELETE work technically; the test API does not really store data.
• Pagination: for posts, comments, photos, and todos the spec uses "type": "page" with _limit and _page; the driver fetches all pages automatically.