insert_into_different_db.ts

import { createClient } from "@clickhouse/client-web";

// Writing to a table that lives in a database other than the client's default `database`.
// Pass a fully qualified `database.table` name to `client.insert`/`client.query`/`client.command`
// when you need to address a different database without recreating the client.
const dbName = "clickhouse_js_examples_web";
const tableName = `test_table_${Math.random().toString(36).slice(2, 8)}`;
const client = createClient({
  database: "system",
});

await client.command({
  query: `CREATE DATABASE IF NOT EXISTS ${dbName}`,
});

// Including the database here, as the client is created for "system"
const fullTableName = `${dbName}.${tableName}`;

await client.command({
  query: `
    CREATE OR REPLACE TABLE ${fullTableName}
    (id UInt32, message String)
    ENGINE MergeTree()
    ORDER BY (id)
  `,
});
console.info(`Created table ${fullTableName}`);

await client.insert({
  table: fullTableName,
  values: [{ id: 42, message: "foo" }],
  format: "JSONEachRow",
});

const rows = await client.query({
  query: `SELECT * FROM ${fullTableName} ORDER BY id, message DESC`,
  format: "JSONEachRow",
});

console.info("Result:", await rows.json());
await client.close();