Add prisma relationMode for PlanetScale

prisma/schema.prisma

@@ -2,14 +2,13 @@
 // learn more about it in the docs: https://pris.ly/d/prisma-schema
 
 datasource db {
-  provider             = "mysql"
-  url                  = env("DATABASE_URL")
-  referentialIntegrity = "prisma"
+  provider     = "mysql"
+  url          = env("DATABASE_URL")
+  relationMode = "prisma"
 }
 
 generator client {
   provider        = "prisma-client-js"
-  previewFeatures = ["referentialIntegrity"]
 }
 
 
@@ -84,6 +83,7 @@ model Post {
   site          Site? @relation(fields: [siteId], references: [id], onDelete: Cascade, onUpdate: Cascade)
   siteId        String?
   @@unique([id, siteId], name: "post_site_constraint")
+  @@index([siteId])
 }
 
 model Site {
@@ -101,6 +101,8 @@ model Site {
   user          User? @relation(fields: [userId], references: [id])
   userId        String?
   posts         Post[]
+
+  @@index([userId])
 }
 
 model Example {