Postgres 14

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CREATE EXTENSION IF NOT EXISTS "uuid-ossp";

CREATE TABLE IF NOT EXISTS site_shipping_method_configuration (
id INT GENERATED ALWAYS AS IDENTITY UNIQUE, /* ==========   UNIQUE CONSTRAINT ADDED  ======   */
shipping_method_id uuid DEFAULT uuid_generate_v4() , 
custom_id VARCHAR(255), 
PRIMARY KEY(shipping_method_id));

CREATE TABLE IF NOT EXISTS public.channel ( 
channel_id integer NOT NULL GENERATED ALWAYS AS IDENTITY, 
channel_name VARCHAR(50), 
PRIMARY KEY(channel_id));

CREATE TABLE IF NOT EXISTS public.shipping_method_channel_mapping ( 
id integer NOT NULL GENERATED ALWAYS AS IDENTITY, 
channel_id integer NOT NULL, 
shipping_method_id integer NOT NULL, 
PRIMARY KEY(id), 
FOREIGN KEY (channel_id) REFERENCES channel (channel_id), 
FOREIGN KEY (shipping_method_id) REFERENCES site_shipping_method_configuration (id));

CREATE EXTENSION

CREATE TABLE

CREATE TABLE

CREATE TABLE

INSERT INTO site_shipping_method_configuration (custom_id) VALUES (1);
INSERT INTO public.channel (channel_name) VALUES ('test channel');

INSERT 0 1

INSERT 0 1

INSERT INTO public.shipping_method_channel_mapping 
(channel_id, shipping_method_id ) VALUES
(1,1);

INSERT 0 1

SELECT * FROM site_shipping_method_configuration;
SELECT * FROM public.channel;
SELECT * FROM public.shipping_method_channel_mapping ;

id
shipping_method_id
custom_id

1
cc7e3cb7-2f0e-429d-b2d4-2112b4cde1ee
1

SELECT 1

channel_id
channel_name

1
test channel

SELECT 1

id
channel_id
shipping_method_id

1
1
1

SELECT 1