use global for prisma

db/index.ts

@@ -1,11 +1,23 @@
 import { BookingStatus, Booking, PrismaClient, Prisma } from '@prisma/client'
 
-const prisma = new PrismaClient()
-
 import { getBookedDays as calendarGetBookedDays } from '../lib/googlecalendar'
 import { uniqueFilter } from '../helpers/array'
 import { dateFormatBackend, getDays, nowInTz } from '../helpers/date'
 
+declare global {
+  // allow global `var` declarations
+  // eslint-disable-next-line no-var
+  var prisma: PrismaClient | undefined
+}
+
+export const prisma =
+  global.prisma ||
+  new PrismaClient({
+    log: ['query'],
+  })
+
+if (process.env.NODE_ENV !== 'production') global.prisma = prisma
+
 export async function getBookedDays(
   uuidsToIngore?: string[]
 ) {