use computed id for UserRepoData (#224)

Author: lihebi

api/prisma/migrations/20230227084111_use_computed_id_for_user_repo_data/migration.sql

@@ -0,0 +1,11 @@
+/*
+  Warnings:
+
+  - The primary key for the `UserRepoData` table will be changed. If it partially fails, the table could be left without primary key constraint.
+  - You are about to drop the column `id` on the `UserRepoData` table. All the data in the column will be lost.
+
+*/
+-- AlterTable
+ALTER TABLE "UserRepoData" DROP CONSTRAINT "UserRepoData_pkey",
+DROP COLUMN "id",
+ADD CONSTRAINT "UserRepoData_pkey" PRIMARY KEY ("userId", "repoId");

api/prisma/schema.prisma

@@ -53,13 +53,15 @@ model User {
 }
 
 model UserRepoData {
-    id         String   @id
     user       User     @relation(fields: [userId], references: [id])
     userId     String
     repo       Repo     @relation(fields: [repoId], references: [id])
     repoId     String
     accessedAt DateTime @default(now()) @updatedAt
     dummyCount Int      @default(0)
+
+    // use computed ID
+    @@id([userId, repoId])
 }
 
 model Repo {