feat: iterator util

Author: subframe7536

README.md

@@ -217,13 +217,18 @@ import {
  exportDatabase,
  importDatabase,
  initSQLiteCore,
+ iterator,
  run,
 } from '@subframe7536/sqlite-wasm'
 
 const core = await initSQLiteCore(/* options */)
 
 await importDatabase(core.vfs, core.path, stream)
 
+for await (const row of iterator(core, 'select * from test')) {
+ console.log(row)
+}
+
 customFunctionCore(core, 'test', num => num)
 await run(core, 'select test(?)', [1])
 

playground/src/index.ts

@@ -119,7 +119,7 @@ document.querySelector('.worker')?.addEventListener('click', async () => {
  }
  worker.postMessage('')
  for await (const data of test()) {
- console.log('iterator', data)
+ console.log('[stream]', data)
  }
 })
 document.querySelector('.importW')?.addEventListener('click', async () => {

playground/src/runSQL.ts

@@ -1,3 +1,5 @@
+import { iterator, type SQLiteDBCore } from '../../src'
+
 export async function runSQL(run: (sql: string, parameters?: any[]) => Promise<any>): Promise<void> {
  await run('CREATE TABLE if not exists t1(a INTEGER, b INTEGER, c VARCHAR);')
  await run('INSERT INTO t1 VALUES(1, 19147, \'nineteen thousand one hundred forty-seven\');')
@@ -16,3 +18,13 @@ export async function runSQLStream(
  await run('INSERT INTO t1 VALUES(3, 46582, \'forty-six thousand five hundred eighty-two\');')
  await stream(onData, 'select * from t1')
 }
+
+export async function runIterator(
+ core: SQLiteDBCore,
+): Promise<void> {
+ const sql = 'INSERT INTO t1 VALUES(100, 19147, \'nineteen thousand one hundred forty-seven\'), (200, 26008, \'twenty-six thousand eight\'), (300, 46582, \'forty-six thousand five hundred eighty-two\');select * from t1;'
+ const it = iterator(core, sql)
+ for await (const row of it) {
+ console.log('[iterator]', row)
+ }
+}

playground/src/worker.ts

@@ -1,8 +1,8 @@
 import { uuidv7 } from 'uuidv7'
 import url from '../../dist/wa-sqlite.wasm?url'
-import { customFunction, initSQLite, isOpfsSupported, withExistDB } from '../../src'
+import { customFunction, initSQLite, isOpfsSupported, iterator, withExistDB } from '../../src'
 import { useOpfsStorage } from '../../src/vfs/opfs'
-import { runSQLStream } from './runSQL'
+import { runIterator, runSQLStream } from './runSQL'
 
 onmessage = async ({ data }) => {
  if (!await isOpfsSupported()) {
@@ -17,10 +17,12 @@ onmessage = async ({ data }) => {
  postMessage(await db.dump())
  return
  }
+
  // if (data) {
  // await db.sync(data)
  // }
  await runSQLStream(db.run, db.stream, data => postMessage(data))
+ await runIterator(db)
  console.log(db.lastInsertRowId(), db.changes())
  customFunction(db.sqlite, db.pointer, 'uuidv7', () => uuidv7())
  console.log(

src/utils.ts

@@ -220,3 +220,21 @@ export async function run(
  await stream(core, data => results.push(data), sql, parameters)
  return results
 }
+
+export async function* iterator(
+ core: SQLiteDBCore,
+ sql: string,
+ parameters?: SQLiteCompatibleType[],
+): AsyncIterableIterator<Record<string, SQLiteCompatibleType>> {
+ const { sqlite, pointer } = core
+ for await (const stmt of sqlite.statements(pointer, sql)) {
+ if (parameters?.length) {
+ sqlite.bind_collection(stmt, parameters)
+ }
+ const cols = sqlite.column_names(stmt)
+ while (await sqlite.step(stmt) === SQLITE_ROW) {
+ const row = sqlite.row(stmt)
+ yield Object.fromEntries(cols.map((key, i) => [key, row[i]]))
+ }
+ }
+}