laconic_postgresql 3.0.0+108

PostgreSQL driver for the Laconic query builder.

laconic_postgresql

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PostgreSQL driver for the Laconic query builder.

Installation

The package declares Dart SDK >=3.7.0 <4.0.0; the currently resolved postgres 3.5.9 requires Dart 3.9 or later. The full workspace also needs Dart 3.10 for its SQLite dependency.

dependencies:
  laconic: ^5.0.0
  laconic_postgresql: ^3.0.0

Usage

import 'package:laconic/laconic.dart';
import 'package:laconic_postgresql/laconic_postgresql.dart';

void main() async {
  final laconic = Laconic(PostgresqlDriver(PostgresqlConfig(
    host: '127.0.0.1',
    port: 5432,
    database: 'my_database',
    username: 'postgres',
    password: 'password',
  )));

  // Query users
  final users = await laconic.table('users').where('active', true).get();

  // Insert data
  final id = await laconic.table('users').insertGetId({
    'name': 'John',
    'age': 25,
  });

  // Update data and get the affected row count
  final updated =
      await laconic.table('users').where('id', id).update({'age': 26});

  // Delete data and get the affected row count
  final deleted = await laconic.table('users').where('id', id).delete();

  // Don't forget to close
  await laconic.close();
}

Configuration

PostgresqlConfig accepts the following parameters:

Parameter	Type	Default	Description
database	String	required	Database name
host	String	'127.0.0.1'	PostgreSQL host address
port	int	5432	Connection port
username	String	'postgres'	Connection username
password	String	required	Connection password
useSsl	bool	true	Whether to use SSL connection

Connection Pooling

The pool opens lazily and allows up to 10 connections. Queries outside a transaction borrow and return a connection; transactions hold one for the entire callback. Prepared statements are cached per reusable physical connection, up to 50 each. Eviction or execution errors dispose statements, and closing a connection removes its cache metadata. Transactions use a separate session cache that is disposed before commit or rollback. Call close() to shut down the pool.

Query Listener

You can add a query listener for debugging:

final laconic = Laconic(
  PostgresqlDriver(PostgresqlConfig(
    database: 'my_database',
    password: 'password',
  )),
  listen: (query) {
    print('SQL: ${query.sql}');
    print('Bindings: ${query.bindings}');
  },
);

Transactions

Await every query inside the transaction callback. Nested transactions on the same driver instance throw LaconicException; savepoints are not created automatically. Different driver instances retain independent transaction contexts.

Transaction queries are pinned to one connection/session and execute serially. You can await queries with Future.wait; each query receives its own result. Calls through another driver instance use that instance's own connection.

await laconic.transaction(() async {
  final userId = await laconic.table('users').insertGetId({
    'name': 'Test User',
  });

  await laconic.table('posts').insert([
    {'user_id': userId, 'title': 'First Post'},
  ]);
});

Parameter binding and raw SQL

Raw clauses and driver queries accept ? or native $1, $2, … parameters. Native numbers in each raw clause start locally at $1; the grammar rebases them when composing the complete query. Repeated $1 references reuse one binding. If both forms occur in one clause, ? parameters follow the largest native index. The binding list must match these positions.

await laconic.table('users').where('active', true)
    .whereRaw(r'id = $1', [7]).get();
await laconic.select('SELECT ?::jsonb ? ? AS found', ['{"key":1}', 'key']);

Question marks inside strings, quoted identifiers, comments and dollar-quoted strings are preserved. PostgreSQL JSON operators ?, ?|, ?& and @? are preserved; ?? explicitly escapes a bare question-mark operator in raw SQL.

Placeholder conversion uses a single scan, and row values share column metadata without intermediate map conversion.

Upgrading from 2.x to 3.0

• Install with laconic: ^5.0.0 and adopt the core 5.0 UNION and cursor-pagination contracts.
• Raw SQL parameters follow the numbering and count validation above; question marks in quoted strings are retained.
• Same-instance nested transactions fail explicitly; calls through other driver instances retain their own connection and transaction context.
• See the CHANGELOG for the complete release notes.

License

MIT License