1、新建应用
使用memfire cloud(https://cloud.memfiredb.com/)并创建免费的账户

2、准备数据表 我们需要准备三张表 Profiles (user information) Posts (thread) Replies (replies)

创建Profiles表

-- Create a table for Public Profiles create table profiles ( id uuid references auth.users not null, updated_at timestamp with time zone, username text unique not null, avatar_url text, website text, point INTEGER DEFAULT 0,

primary key (id), unique(username), constraint username_length check (char_length(username) >= 3) );

alter table profiles enable row level security;

create policy "Public profiles are viewable by everyone." on profiles for select using ( true );

create policy "Users can insert their own profile." on profiles for insert with check ( auth.uid() = id );

create policy "Users can update own profile." on profiles for update using ( auth.uid() = id );

创建avatars存储桶，用于存储用户头像

-- Set up Storage! insert into storage.buckets (id, name) values ('avatars', 'avatars');

create policy "Avatar are public accessible." on storage.objects for select using ( bucket_id = 'avatars' );

create policy "Everyone can upload an avatar." on storage.objects for insert with check ( bucket_id = 'avatars' );

create policy "Everyone can update an avatar." on storage.objects for update with check ( bucket_id = 'avatars' );

创建Posts表

CREATE TABLE posts ( id uuid NOT NULL DEFAULT uuid_generate_v4() PRIMARY KEY, user_id uuid not null, title text not null, body text not null, slug text not null, tag text not null, vote INTEGER DEFAULT 0, created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP, updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP, CONSTRAINT fk_user FOREIGN KEY(user_id) REFERENCES profiles(id) ON DELETE SET NULL );

alter table posts enable row level security;

create policy "Individuals can create posts." on posts for insert with check (auth.uid() = user_id);

create policy "Individuals can update their own posts." on posts for update using (auth.uid() = user_id);

create policy "Individuals can delete their own posts." on posts for delete using (auth.uid() = user_id);

create policy "Posts are public." on posts for select using (true);

创建Replies表

CREATE TABLE replies ( id uuid NOT NULL DEFAULT uuid_generate_v4() PRIMARY KEY, body text, user_id uuid not null, post_id uuid, vote INTEGER DEFAULT 0, created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP, updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP, CONSTRAINT fk_post FOREIGN KEY(post_id) REFERENCES posts(id) ON DELETE SET NULL, CONSTRAINT fk_user FOREIGN KEY(user_id) REFERENCES profiles(id) ON DELETE SET NULL );

alter table replies enable row level security;

create policy "Individuals can create replies." on replies for insert with check (auth.uid() = user_id);

create policy "Individuals can update their own replies." on replies for update using (auth.uid() = user_id);

create policy "Individuals can delete their own replies." on replies for delete using (auth.uid() = user_id);

create policy "replies are public." on replies for select using (true);

设置 postgre 函数以触发更新时间 CREATE OR REPLACE FUNCTION set_timestamp(post_id uuid) RETURNS void AS $$ BEGIN UPDATE posts SET updated_at = NOW() WHERE id = post_id; END; $$ LANGUAGE plpgsql;