how to define many-to-many relationship in prisma/psql - sql

Question

I'm struggling a bunch with some relatively simple Postgres that I was originally trying to define in Prisma but wasn't having much luck. It's a many to many relationship joined on a single field between two tables as such:
CREATE TABLE scheduleDate (
schedule_day_number int NOT NULL
, schedule_date date NOT NULL
,CONSTRAINT scheduledate_pkey PRIMARY KEY (schedule_date, schedule_day_number)
);
CREATE TABLE schoolDayBlock (
start_time varchar(10) NOT NULL
, end_time varchar(10) NOT NULL
,school_block_day_number int NOT NULL
, block_name varchar(10) NOT NULL
,CONSTRAINT schooldayblock_pkey PRIMARY KEY (start_time, end_time, school_block_day_number, block_name )
);
I eventually want to be able to get all the possible combinations between these two tables with the day number fields being the link. Ideally, later down the line, I can query Prisma for a block name and get all of the dates and times where that block name shows up. Does anyone know how I could
Write this up in a Prisma schema or
Write this up in postgres.sql and use introspection to generate a Prisma schema that accomplishes this.

Answer 1

Here's the prisma schema equivalent of your SQL query for creating two tables.
// This is your Prisma schema file,
// learn more about it in the docs: https://pris.ly/d/prisma-schema
generator client {
provider = "prisma-client-js"
}
datasource db {
provider = "postgresql"
url = env("DATABASE_URL")
}
model scheduleDate {
schedule_day_number Int
schedule_date DateTime
##id([schedule_day_number, schedule_date], name: "scheduledate_pkey")
}
model schoolDayBlock {
start_time DateTime
end_time DateTime
school_block_day_number Int
block_name String
##id([start_time, end_time, school_block_day_number, block_name], name: "schooldayblock_pkey")
}