import { Savepoint } from "https://deno.land/x/postgres@v0.19.2/mod.ts";
Updating a savepoint will update its position in the transaction execution
import { Client } from "https://deno.land/x/postgres/mod.ts";
const client = new Client();
const transaction = client.createTransaction("transaction");
const my_value = "some value";
const savepoint = await transaction.savepoint("n1");
transaction.queryArray`INSERT INTO MY_TABLE (X) VALUES (${my_value})`;
await savepoint.update(); // Rolling back will now return you to this point on the transaction
You can also undo a savepoint update by using the release
method
import { Client } from "https://deno.land/x/postgres/mod.ts";
const client = new Client();
const transaction = client.createTransaction("transaction");
const savepoint = await transaction.savepoint("n1");
transaction.queryArray`DELETE FROM VERY_IMPORTANT_TABLE`;
await savepoint.update(); // Oops, shouldn't have updated the savepoint
await savepoint.release(); // This will undo the last update and return the savepoint to the first instance
await transaction.rollback(); // Will rollback before the table was deleted