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CrateDB HTTP API Client for Node.js

This library is a lightweight Node.js client derived from node-crate for interacting with CrateDB via its HTTP endpoint. Unlike libraries such as node-postgres, which use the PostgreSQL wire protocol, this client communicates with CrateDB's native HTTP API.

Caution

This library is primarily a proof of concept.
While it provides basic functionality to interact with CrateDB, it is not production-ready and lacks the robustness of established libraries.

For production use, consider mature libraries like node-postgres which leverage CrateDB's PostgreSQL compatibility. Use this client only for testing, experimentation, or if you know what you're doing. 😉

Configuration

The CrateDBClient can be configured with either environment variables or directly with an options object. Below are the configuration options, along with their default values.

Configuration Options

Option Type Default Value Description
user string 'crate' or process.env.CRATEDB_USER Database user.
password string or null '' or process.env.CRATEDB_PASSWORD Database password.
host string 'localhost' or process.env.CRATEDB_HOST Database host.
port number 4200 or process.env.CRATEDB_PORT Database port.
defaultSchema string 'doc' or process.env.CRATEDB_DEFAULT_SCHEMA Default schema for queries.
connectionString string null Connection string, e.g., https://user:password@host:port/.
ssl object or null null SSL configuration;
keepAlive boolean true Enables HTTP keep-alive for persistent connections.
maxConnections number 20 Limits the maximum number of concurrent connections.

Environment Variables

Alternatively, you can set these variables in your environment:

export CRATEDB_USER=crate
export CRATEDB_PASSWORD=secretpassword
export CRATEDB_HOST=my.database-server.com
export CRATEDB_PORT=4200
export CRATEDB_DEFAULT_SCHEMA=doc

Usage

To use the CrateDBClient:

  1. Import the CrateDBClient class.
  2. Instantiate it with your configuration options.
  3. Call any of the CRUD and DDL methods provided.
import { CrateDBClient } from './CrateDBClient.js';

const client = new CrateDBClient({
  user: 'database-user',
  password: 'secretpassword!!',
  host: 'my.database-server.com',
  port: 5334,
  defaultSchema: 'my_schema',
  keepAlive: true, // Enable persistent connections
  maxConnections: 20  // Limit to 20 concurrent sockets
});

General Operations

executeSql(sql, args)

Execute a raw SQL query.

await client.executeSql('SELECT * FROM my_table';);
await client.executeSql('SELECT * FROM my_table', []);

streamQuery(sql, batchSize)

The streamQuery method in CrateDBClient wraps the CrateDBCursor functionality for convenient query streaming. This method automatically manages the cursor’s lifecycle.

Streams query results row by row using an async generator. The batchSize determines the number of rows fetched per request (default is 100).

for await (const row of client.streamQuery('SELECT * FROM my_table ORDER BY id', 5)) {
  console.log(row); // Process each row individually
}

CRUD Operations

insert(tableName, obj, primaryKeys = null)

Insert a new row into a specified table with optional primary key conflict resolution.

  • tableName: The name of the table to insert the row into.
  • obj: An object representing the row to insert.
  • primaryKeys: (Optional) An array of column names to use as primary keys for conflict resolution.

If primaryKeys are provided, the method will handle conflicts by updating the non-primary key fields of conflicting rows. If no primaryKeys are provided, conflicting rows will be skipped.

// Insert a row with primary key conflict resolution
await client.insert("my_table", { id: 1, column1: "value1", column2: "value2" }, ["id"]);

// Insert a row without conflict resolution
await client.insert("my_table", { id: 1, column1: "value1", column2: "value2" });

insertMany(tableName, jsonArray, primaryKeys = null)

Insert multiple rows into a table with optional primary key conflict resolution.

  • tableName: The name of the table to insert rows into.
  • jsonArray: An array of objects representing rows to insert.
  • primaryKeys: (Optional) An array of column names to use as primary keys for conflict resolution.

If primaryKeys are provided, the method will handle conflicts by updating the non-primary key fields of conflicting rows. If no primaryKeys are provided, conflicting rows will be skipped.

const bulkData = [
  { id: 1, name: "Earth", kind: "Planet", description: "A beautiful place." },
  { id: 2, name: "Mars", kind: "Planet", description: "The red planet." },
  { id: 1, name: "Earth Updated", kind: "Planet", description: "Updated description." }, // Conflict on id
];

await client.insertMany("my_table", bulkData, ["id"]);
// Conflicting row with `id: 1` will be updated instead of skipped.

await client.insertMany("my_table", bulkData);
// Conflicting rows will be skipped as no `primaryKeys` are provided.

update(tableName, options, whereClause)

Update rows in a table that match a WHERE clause.

await client.update('my_table', { column1: 'new_value' }, 'column2 = value2');

delete(tableName, whereClause)

Delete rows from a table that match a WHERE clause.

await client.delete('my_table', 'column1 = value1');

drop(tableName)

Drop a specified table.

await client.drop('my_table');

createTable(schema)

Create a new table based on a schema definition.

await client.createTable({
  my_table: {
    id: 'INTEGER PRIMARY KEY',
    name: 'STRING',
    created_at: 'TIMESTAMP'
  }
});

Cursor Operations

createCursor(sql)

Create a cursor to fetch large datasets efficiently.

const cursor = client.createCursor('SELECT * FROM my_table ORDER BY id');
await cursor.open();

console.log(await cursor.fetchone()); // Fetch one record
console.log(await cursor.fetchmany(5)); // Fetch 5 records
console.log(await cursor.fetchall()); // Fetch all remaining records

await cursor.close(); // Close the cursor and commit the transaction

iterate(batchSize)

Creates an async generator that fetches query results in chunks of size batchSize (default is 100).

const cursor = client.createCursor('SELECT * FROM my_table ORDER BY id');
await cursor.open();

for await (const row of cursor.iterate(5)) {
  console.log(row); // Process each row individually
}

await cursor.close();

Connection Management

Configure keepAlive for persistent connections and maxConnections to limit concurrent connections.

const client = new CrateDBClient({
  user: 'database-user',
  password: 'secretpassword!!',
  host: 'my.database-server.com',
  port: 4200,
  ssl: true,             // Use HTTPS
  keepAlive: true,       // Enable persistent connections
  maxConnections: 20,         // Limit to 10 concurrent sockets
  defaultSchema: 'my_schema' // Default schema for queries
});

License

MIT License. Feel free to use and modify this library as per the terms of the license.

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A lightweight Node.js client for CrateDB.

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