Fetch from the Network

Here introduce the method use JavaScript's fetch API to load remote files directly into the virtual file system.

WARNING

This approach may be affected by CORS policy.

Usage

To fetch a file from the network and write it to the Emscripten file system, you can use the following approach:

const response = await fetch("https://raw.githubusercontent.com/kuzudb/kuzu/master/dataset/demo-db/csv/follows.csv");
const dataArrayBuffer = new Uint8Array(await response.arrayBuffer());
kuzu.FS.writeFile("/follows.csv", dataArrayBuffer);

This code fetches a CSV file from the network, converts it to a format that Emscripten’s file system can handle Uint8Array, and writes it into the virtual file system.

Full Example

The following example demonstrates fetching a CSV file from a remote URL, storing it in the Emscripten file system, and importing it into a Kuzu database.

// Step 1: Initialize the Kuzu Database
const db = await kuzu.Database();

// Step 2: Create a connection to the database
const conn = await kuzu.Connection(db);

// Step 3: Fetch the CSV file from a remote server
const response = await fetch("https://raw.githubusercontent.com/kuzudb/kuzu/master/dataset/demo-db/csv/follows.csv");
const dataArrayBuffer = new Uint8Array(await response.arrayBuffer());

// Step 4: Write the fetched file to the Emscripten virtual file system
kuzu.FS.writeFile("/follows.csv", dataArrayBuffer);

// Step 5: Read the content of the file from the virtual file system to verify
const fileContent = kuzu.FS.readFile("/follows.csv", { encoding: 'utf8' });
console.log("File Content:\n", fileContent);

// Step 6: Create a table for the 'Follows' data in the database
await conn.execute("CREATE NODE TABLE Follows(user1 STRING, user2 STRING)");

// Step 7: Import data from the fetched CSV file into the 'Follows' table
await conn.execute('COPY Follows FROM "/follows.csv";');