add support for postgresql driver in function sdk

[mangalaman93]

Completes HYP-1323
Also completes HYP-1324

[mattjohnsonpint]

This isn't great. The user shouldn't have to turn everything into a string.

It also means that we're passing all parameters as strings into Postgres, such as:

["John","42,123.45","[1,2,3,4]","2024-06-19T23:59:59.999Z","true","(123.45,-67.89)"]

The existing QueryVariables class could be re-purposed here, which would turn this code into something like:

  const params = new QueryVariables();
  params.set("$1", name);
  params.set("$2", age);
  params.set("$3", balance);
  params.set("$4", privkey);
  params.set("$5", new Date(Date.now()));
  params.set("$6", male);
  params.set("$7", `(${lat},${lon})`);

  postgresql.query("neon", query, params);

However, since postgres only use positional parameters (unlike SQL Server and others that use named parameters), we should make a new class in our library:

export class QueryParameters {
  private data: string[] = [];

  public add<T>(value: T): void {
    this.data.push(JSON.stringify(value));
  }

  public toJSON(): string {
    return `[${this.data.join(",")}]`;
  }
}

Then the usage can be:

  const params = new QueryParameters();
  params.add(name);
  params.add(age);
  params.add(balance);
  params.add(privkey);
  params.add(new Date(Date.now()));
  params.add(male);
  params.add(`(${lat},${lon})`);

  postgresql.query("neon", query, params);

The resulting JSON array would then not contain only strings, but for example:

["John",42,123.45,[1,2,3,4],"2024-06-19T23:59:59.999Z",true,"(123.45,-67.89)"]

[mattjohnsonpint]

Also you could try passing the lat/lon as an array - I'm not sure how Postges needs it though.

params.add(<f32[]>[lat, lon]);

[mattjohnsonpint]

Suggested change

	privkey: i8[],
	privkey: u8[],

Or:

Suggested change

	privkey: i8[],
	privkey: Uint8Array,

Or:

Suggested change

	privkey: i8[],
	privkey: ArrayBuffer,

Ideally the runtime should support all three (we should test that), but either way it would be unsigned.

[mattjohnsonpint]

Lets pass query and params as two separate variable to the host function. That will reduce some JSON work for the query, and will make it easier to use the QueryParameters object mentioned in the comment in the example.

Suggested change

	const input: pgInput = {
	query: query,
	params: params,
	};
	const respStr = host.databaseQuery(
	datasourceName,
	datasourceType,
	JSON.stringify<pgInput>(input),
	);
	const respStr = host.databaseQuery(
	datasourceName,
	datasourceType,
	query,
	params.toJSON()
	);

[mattjohnsonpint]

This example is to get a person, but instead we get a string - which the user would have to decide how to parse. Since we're the ones in control over how the API returns data, we should return it already parsed to the format that the user is expecting. In other words, the user should not have to think too much about JSON to interpret the results.

To achieve that, the user can pass in an object to be populated as a generic type parameter. This pattern is already being used on the GraphQL example.

That also gives the user an opportunity to see how to use the results in their own application logic.

In other words:

Suggested change

	export function getPerson(name: string): string {
	const query = "select * from people where name = $1";
	return postgresql.query("neon", query, [name]);
	}
	export function getPerson(name: string): Person {
	const query = "select * from people where name = $1";
	const people = postgresql.query<Person>("neon", query, [name]); // or params object, etc.
	if (people.length == 0) {
	throw new Error(`Person not found named ${name}.`);
	}
	if (people.length > 1) {
	throw new Error(`More than one person found named ${name}.`);
	}
	return people[0];
	}

[mattjohnsonpint]

Suggested change

	export function queryPeople(): string {
	return postgresql.query("neon", "select * from people", []);
	}
	export function queryPeople(): Person[] {
	return postgresql.query<Person>("neon", "select * from people");
	}

(see feedback on getPerson example)

[mattjohnsonpint]

Suggested change

	static query(
	datasourceName: string,
	query: string,
	params: string[],
	): string {
	static query<TData>(
	datasourceName: string,
	query: string,
	params: QueryParameters | null = null,
	): TData[] {

see feedback on the examples.

[socket-security]

New and removed dependencies detected. Learn more about Socket for GitHub ↗︎

Package	New capabilities	Transitives	Size	Publisher
npm/@typescript-eslint/eslint-plugin@7.13.0	None	+6	4.55 MB	jameshenry
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[mattjohnsonpint]

Updated by #119 (which includes much of this)
Thanks.