Type mismatch in Union queries

[yknevenky]

const result = await db
  .select({
    id: entity.id,
    email: entity.emailAddress,
    userCustomId: entity.id,
    role: sql<string>`${UserRole.Entity}`,
  })
  .from(entityTable)
  .where(
    and(
      eq(entity.id, uniqueId),
      isNull(studentEntity.emailAddress),
      isNull(facultyEntity.emailAddress)
    )
  )
  .leftJoin(studentEntity, eq(studentEntity.userCustomId, entity.id))
  .leftJoin(facultyEntity, eq(facultyEntity.userCustomId, entity.id))
  
  .unionAll(
    db
      .select({
        id: adminEntity.id,
        email: adminEntity.emailAddress,
        userCustomId: adminEntity.id,
        role: sql<string>`${UserRole.Admin}`,
      })
      .from(adminEntityTable)
      .where(eq(adminEntity.id, uniqueId))
  )
  .unionAll(
    db
      .select({
        id: studentEntity.id,
        email: studentEntity.emailAddress,
        userCustomId: studentEntity.userCustomId,
        role: sql<string>`${UserRole.Student}`,
      })
      .from(studentEntityTable)
      .where(eq(studentEntity.id, uniqueId))
  )
  .unionAll(
    db
      .select({
        id: facultyEntity.id,
        email: facultyEntity.emailAddress,
        userCustomId: facultyEntity.userCustomId,
        role: sql<string>`${UserRole.Faculty}`,
      })
      .from(facultyEntityTable)
      .where(eq(facultyEntity.id, uniqueId))
  )
  .unionAll(
    db
      .select({
        id: departmentEntity.id,
        email: departmentEntity.emailAddress,
        userCustomId: departmentEntity.id,
        role: sql<string>`${UserRole.AcademicDepartmentAdmin}`,
      })
      .from(departmentEntityTable)
      .where(eq(departmentEntity.id, uniqueId))
  )
  .limit(1);

Type '{ id: string; email: string | null; userCustomId: string | null; role: string; }[]' is not assignable to type '{ id: string; email: string | null; userCustomId: string; role: string; }[]'.
  Type '{ id: string; email: string | null; userCustomId: string | null; role: string; }' is not assignable to type '{ id: string; email: string | null; userCustomId: string; role: string; }'.
    Types of property 'userCustomId' are incompatible.
      Type 'string | null' is not assignable to type 'string'.
        Type 'null' is not assignable to type 'string'.

I am facing issues where the userCustomId in the first select has a non nullable type but the union queries can have userCustomId null values. How do I make the userCustomId nullable here. Also userCustomId is an alias, not a column, is that the issue here?? I am new drizzle, so not sure how to type the alias in the first query so that he union queries types will match.

db.select({
    id: entity.id,
    email: entity.emailAddress,
    userCustomId: entity.id,
    role: sql<string>`${UserRole.Standard}`,
  }).from(entityTable)