update DB schema

@@ -9,44 +9,47 @@ datasource db {
 }
 
 model User {
-  id             Int       @default(autoincrement()) @id
-  avatarUrl      String?   @default("")
-  email          String    @unique
-  password       String
-  username       String
-  phoneNum       String    @default("") @unique
-  emailSecret    String?   @default("")
-  phoneSecret    String?   @default("")
-  bio            String?   @default("")
-  rooms          Room[]    @relation(references: [id])
-  sendMessage    Message[] @relation("Sender")
-  receiveMessage Message[] @relation("Receiver")
-  createdAt      DateTime? @default(now())
+  id          Int       @default(autoincrement()) @id
+  avatarUrl   String?   @default("")
+  email       String    @unique
+  password    String
+  username    String
+  phoneNum    String    @default("") @unique
+  emailSecret String?   @default("")
+  phoneSecret String?   @default("")
+  bio         String?   @default("")
+  room        Room      @relation(fields: [roomId], references: [id])
+  roomId      Int
+  messages    Message[]
+  sender      User      @relation("SenderReceiver", fields: [id], references: [id])
+  receiver    User?     @relation("SenderReceiver")
+  createdAt   DateTime? @default(now())
 }
 
 model Room {
   id           Int        @default(autoincrement()) @id
   name         String
-  participants User[]     @relation(references: [id])
+  participants User[]
   categories   Category[]
-  Message      Message[]
+  messages     Message[]
 }
 
 model Category {
-  id      Int     @default(autoincrement()) @id
-  name    String? @default("")
-  SubRoom Int
-  room    Room    @relation(fields: [SubRoom], references: [id])
+  id       Int       @default(autoincrement()) @id
+  name     String?   @default("")
+  room     Room      @relation(fields: [roomId], references: [id])
+  roomId   Int
+  messages Message[]
 }
 
 model Message {
-  id        Int       @default(autoincrement()) @id
-  text      String?   @default("")
-  from      User      @relation("Sender", fields: [fromId], references: [id])
-  fromId    Int
-  to        User?     @relation("Receiver", fields: [toId], references: [id])
-  toId      Int?
-  room      Room      @relation(fields: [roomId], references: [id])
-  roomId    Int
-  createdAt DateTime? @default(now())
+  id         Int       @default(autoincrement()) @id
+  text       String    @default("")
+  sender     User      @relation(fields: [senderId], references: [id])
+  senderId   Int
+  room       Room      @relation(fields: [roomId], references: [id])
+  roomId     Int
+  createdAt  DateTime? @default(now())
+  category   Category? @relation(fields: [categoryId], references: [id])
+  categoryId Int?
 }
\ No newline at end of file