@ladc/pg-adapter

LADC is a common API on top of relational database (SQL) connectors. It can connect to Postgresql, MariaDB / MySQL, SQLite. The API is inspired from PDO and JDBC. It’s named LADC for “a Layer Above Database Connectors”.

This package is a plugin for LADC. It is an adapter for Postgresql, using the connector pg.

Install

npm install @ladc/pg-adapter ladc

Usage

How to create a connection:

import ladc from "ladc";
import pgAdapter from "@ladc/pg-adapter";

const cn = ladc({
  adapter: pgAdapter({
    pgConfig: {
      host: "-my-server-",
      database: "-my-database-",
      user: "-my-user-",
      password: "-my-password-",
    },
  }),
});

How to Retrieve the Last Inserted Identifier with Postgresql

Postgresql has a gotcha regarding autoincremented identifiers. The insert query must end with a non-standard returning statement. Then, the name of the autoincremented column is required to obtain its last inserted value.

The LADC adapter for Postgresql provides the autoincMapping option. It allows to provide a mapping of autoincremented column name for each table that has one. Here is an example:

const autoincMapping = {
  test: "test_id",
};

const cn = ladc({
  adapter: pgAdapter({
    pgConfig: {
      /* credentials */
    },
    autoincMapping,
  }),
});

// The adapter will append 'returning test_id'
const result = await cn.exec(
  "insert into test (message) values ('Hello, World!')"
);

// Returns the value of 'test_id'
const newId = result.getInsertedId();

Or, it is still possible to manually write the returning statement then to get it:

const result = await cn.exec(
  "insert into test(message) values ('Hi there!') returning test_id" // Postgres only
);
const newId = result.getInsertedId("test_id");

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