small add

Author: bradwestfall

lessons/02-promises/lecture/NOTES.md

@@ -116,4 +116,11 @@ getPersonVehicles(1)
   .then((allVehicles) => {
     console.log(allVehicles)
   })
+
+// ----------------
+// 7. Show database connection and wrapping callbacks in promises
+
+import { query } from './db'
+
+query('SELECT * FROM user').then((results) => {})
 ```

lessons/02-promises/lecture/db.ts

@@ -0,0 +1,18 @@
+import path from 'path'
+import sqlite3 from 'sqlite3'
+
+const db = new sqlite3.Database(path.resolve(process.cwd(), 'database.db'))
+
+export function query(sql: string) {
+  return new Promise((resolve, reject) => {
+    db.all(sql, (err, rows) => {
+      if (err) {
+        reject(err.message)
+      } else {
+        resolve(rows || [])
+      }
+    })
+  })
+}
+
+// query('SELECT * FROM user').then(results => {})