gem-hunter
主要言語: Dart
Dart PostgreSQL driver: supports extended query format, binary protocol and statement reuse.
A library for connecting to and querying PostgreSQL databases (see Postgres Protocol). This driver uses the more efficient and secure extended query format of the PostgreSQL protocol.
Create a Connection:
final conn = await Connection.open(Endpoint( host: 'localhost', database: 'postgres', username: 'user', password: 'pass', ));
Execute queries with execute:
final result = await conn.execute("SELECT 'foo'"); print(result[0][0]); // first row and first field
Named parameters, returning rows as map of column names:
final result = await conn.execute( Sql.named('SELECT * FROM a_table WHERE id=@id'), parameters: {'id': 'xyz'}, ); print(result.first.toColumnMap());
Execute queries in a transaction:
await conn.runTx((s) async { final rs = await s.execute('SELECT count(*) FROM foo'); await s.execute( r'UPDATE a_table SET totals=$1 WHERE id=$2', parameters: [rs[0][0], 'xyz'], ); });
See the API documentation: https://pub.dev/documentation/postgres/latest/
The package supports connection strings for both single connections and connection pools:
await Connection.openFromUrl('postgresql://localhost/mydb'); await Connection.openFromUrl( 'postgresql://user:pass@db.example.com:5432/production?sslmode=verify-full' ); await Connection.openFromUrl( 'postgresql://localhost/mydb?connect_timeout=10&query_timeout=60' ); Pool.withUrl( 'postgresql://localhost/mydb?max_connection_count=10&max_connection_age=3600' );
postgresql://[userspec@][hostspec][:port][/dbname][?paramspec]
postgresql:// or postgres://username or username:password (can also be set via user/username and password query parameters)localhost). Supports multiple hosts via comma-separated list (host1:5433,host2:5434) or multiple host query parameters (?host=host1:5433&host=host2:5434)5432, can be overridden via port query parameter)postgres, can be overridden via database query parameter)These parameters are supported by Connection.openFromUrl():
| Parameter | Type | Description | Example Values |
|---|---|---|---|
application_name |
String | Sets the application name | application_name=myapp |
client_encoding |
String | Character encoding | UTF8, LATIN1 |
connect_timeout |
Integer | Connection timeout in seconds | connect_timeout=30 |
database |
String | Database name (overrides URL path) | database=mydb |
host |
String | Alternative host specification (supports Unix sockets) | host=/var/run/postgresql, host=host1:5433 |
password |
String | Password (overrides URL userspec) | password=secret |
port |
Integer | Port number (overrides URL port) | port=5433 |
user / username |
String | Username (overrides URL userspec) | user=myuser |
sslmode |
String | SSL mode | disable, require, verify-ca, verify-full |
sslcert |
String | Path to client certificate | sslcert=/path/to/cert.pem |
sslkey |
String | Path to client private key | sslkey=/path/to/key.pem |
sslrootcert |
String | Path to root certificate | sslrootcert=/path/to/ca.pem |
replication |
String | Replication mode | database (logical), true/physical, false/no_select (none) |
query_timeout |
Integer | Query timeout in seconds | query_timeout=300 |
These additional parameters are supported by Pool.withUrl():
| Parameter | Type | Description | Example Values |
|---|---|---|---|
max_connection_count |
Integer | Maximum number of concurrent connections | max_connection_count=20 |
max_connection_age |
Integer | Maximum connection lifetime in seconds | max_connection_age=3600 |
max_session_use |
Integer | Maximum session duration in seconds | max_session_use=600 |
max_query_count |
Integer | Maximum queries per connection | max_query_count=1000 |
The library supports connection pooling (and masking the connection pool as regular session executor).
The library supports registering custom type codecs (and generic object encoders)
through theConnectionSettings.typeRegistry.
The library supports connecting to PostgreSQL using the Streaming Replication Protocol. See Connection documentation for more info. An example can also be found at the following repository: postgresql-dart-replication-example
This library originally started as StableKernel's postgres library, but got a full API overhaul and partial rewrite of the internals.
Please file feature requests and bugs at the issue tracker.