目标要高，因为“胆小的人和勇敢的人一样容易被抓住” —— 海伦·凯勒

Deno - Edge Functions

Key Points

1. Database Function

1.4 How to create one database function

1.4.1 One simple function

               
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               create or replace function hello_world() -- 1
returns text -- 2
language sql -- 3
as $$  -- 4
  select 'hello world';  -- 5
$$; --6


               COPY
             

At it's most basic a function has the following parts:

• create or replace function hello_world(): The function declaration, where hello_world is the name of the function. You can use either create when creating a new function or replace when replacing an existing function. Or you can use create or replace together to handle either.
• returns text: The type of data that the function returns. If it returns nothing, you can returns void.
• language sql: The language used inside the function body. This can also be a procedural language: plpgsql, plv8, plpython, etc.
• as $$: The function wrapper. Anything enclosed inside the $$ symbols will be part of the function body.
• select 'hello world';: A simple function body. The final select statement inside a function body will be returned if there are no statements following it.
• $$;: The closing symbols of the function wrapper.

2. Database Functions vs Edge Functions

For data-intensive operations, use Database Functions, which are executed within your database and can be called remotely using the REST and GraphQL API.

For use-cases which require low-latency, use Edge Functions, which are globally-distributed and can be written in Typescript.

FAQs - for self-hosting

1. The schema must be one of the following: public, storage, graphql_public

1.1 error info:

               
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               {
  "code": "PGRST106",
  "details": null,
  "hint": null,
  "message": "The schema must be one of the following: public, storage, graphql_public"
}

               COPY
             

1.2 solutions

• To config api.schemas in config.toml file, #issues - 18444 

2. AI Relevant

2.1 How to set open ai key in .env file?

• You'll need to provide your own OPENAI_KEY in your env file. (Note Open AI is expecting the default OPENAI_API_KEY, but in our code we've renamed it OPENAI_KEY, so that's what you'll have to name yours as well.) #issues - 21621 

3. Using Custom Schemas

Go To 

Appendix

1. deno installion - https://docs.deno.com/runtime/getting_started/installation/ 
2. jsr.io - https://jsr.io/ 
3. esm.sh - https://esm.sh/ 

Create modern(es2015+) web apps easily with NPM packages in browser/deno.