make usernames unique

backend/src/api.js

@@ -51,15 +51,15 @@ router.get("/healthcheck", (req, res) => {
  *               input_method: 1
  */
 router.post("/users", async (req, res) => {
-    const { username, input_method = 0 } = req.body;
-
     const [result] = await pool.query(
-        "INSERT INTO users (username, input_method) VALUES (?, ?)",
+        `INSERT INTO users (username, input_method) 
+         VALUES (?, ?)
+         ON DUPLICATE KEY UPDATE id = LAST_INSERT_ID(id)`,
         [username, input_method]
     );
 
     const [userRow] = await pool.query("SELECT * FROM users WHERE id = ?", [result.insertId]);
-    res.status(201).json(userRow[0]);
+    res.status(200).json(userRow[0]);
 });
 
 /**