diff --git a/src/idz/db/_util.ts b/src/idz/db/_util.ts
new file mode 100644
index 0000000..6be4494
--- /dev/null
+++ b/src/idz/db/_util.ts
@@ -0,0 +1,25 @@
+import * as sql from "sql-bricks";
+import { Client } from "pg";
+
+import { ExtId } from "../model/base";
+import { Profile } from "../model/profile";
+import { Id } from "../../db";
+
+export async function _findProfile(
+  conn: Client,
+  extId: ExtId<Profile>
+): Promise<Id<Profile> | undefined> {
+  const lookupSql = sql
+    .select("r.id")
+    .from("idz.profile r")
+    .where("r.ext_id", extId)
+    .toParams();
+
+  const { rows } = await conn.query(lookupSql);
+
+  if (rows.length > 0) {
+    return rows[0].id as Id<Profile>;
+  } else {
+    throw new Error("Profile not found");
+  }
+}