IdentifiablePostgresPersistence<T, K>

Inherits: PostgresPersistence

Description

The IdentifiablePostgresPersistence class allows you to create persistence components that store data in PostgreSQL databases and implement a number of CRUD operations over data items with unique ids.

Important points

• The data items must implement the IIdentifiable interface.
• In basic scenarios, child classes shall only override the getPageByFilter, getListByFilter or deleteByFilter operations with a specific filter function.
• All other operations can be used out of the box.
• In complex scenarios, child classes can implement additional operations by accessing this._collection and this._model properties.

Configuration parameters

• collection: (optional) Postgres collection name

connection(s):

• discovery_key: (optional) key to retrieve the connection from IDiscovery
• host: host name or IP address
• port: port number (default: 27017)
• uri: resource URI or connection string with all parameters in it

credential(s):

• store_key: (optional) key to retrieve the credentials from ICredentialStore
• username: (optional) username
• password: (optional) user’s password

options:

• max_pool_size: (optional) maximum connection pool size (default: 2)
• keep_alive: (optional) enable connection keep alive (default: true)
• connect_timeout: (optional) connection timeout in milliseconds (default: 5 sec)
• auto_reconnect: (optional) enable auto reconnection (default: true)
• max_page_size: (optional) maximum page size (default: 100)
• debug: (optional) enable debug output (default: false).

References

• *:logger:*:*:1.0 - (optional) ILogger components to pass log messages
• *:discovery:*:*:1.0 - (optional) IDiscovery services
• *:credential-store:*:*:1.0 - (optional) credential stores to resolve credentials (ICredentialStore)

Constructors

Creates a new instance of the persistence component.

public IdentifiablePostgresPersistence(string tableName)

• tableName: string - (optional) collection name.

Fields

Instance methods

CreateAsync

Creates a data item.

public override Task<T> CreateAsync(string correlationId, T item)

• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• item: T - item to be created.
• returns: Task<T> - created item

DeleteByIdAsync

Deletes a data item by it’s unique id.

public virtual Task<T> DeleteByIdAsync(string correlationId, K id)

• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• id: K - id of the item to be deleted
• returns: Task<T> - deleted item

DeleteByIdsAsync

Deletes multiple data items by their unique ids.

public virtual Task DeleteByIdsAsync(string correlationId, K[] ids)

• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• ids: K[] - ids of data items to be deleted.

GetListByIdsAsync

Gets a list of data items retrieved by given unique ids.

public virtual Task<List<T>> GetListByIdsAsync(string correlationId, K[] ids)

• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• ids: K[] - ids of data items to be retrieved
• returns: Task<List<T>> - data list

GetOneByIdAsync

Gets a data item by its unique id.

public virtual Task<T> GetOneByIdAsync(string correlationId, K id)

• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• id: K - id of data item to be retrieved.
• returns: Task<T> - data item

SetAsync

Sets a data item. If the data item exists, it updates it. Otherwise, it creates a new data item.

public virtual Task<T> SetAsync(string correlationId, T item)

• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• item: T - item to be set.
• returns: Task<T> - updated item

UpdateAsync

Updates a data item.

public virtual Task<T> UpdateAsync(string correlationId, T item)

• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• item: T - item to be updated.
• returns: Task<T> - updated item

UpdatePartially

Updates only a few selected fields in a data item.

public virtual Task<T> UpdatePartially(string correlationId, K id, AnyValueMap data)

• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• id: K - id of the data item to be updated.
• data: AnyValueMap - map with fields to be updated.
• returns: Task<T> - updated item

Examples

class MyPostgresPersistence: PostgresPersistence<MyData, string> 
{
    public MyPostgresPersistence(): base("mydata") { }

    private FilterDefinition<MyData> ComposeFilter(FilterParams filter)
    {
        filterParams = filterParams ?? new FilterParams();
        var builder = Builders<BeaconV1>.Filter;
        var filter = builder.Empty;
        String name = filter.getAsNullableString("name");
        if (name != null)
            filter &= builder.Eq(b => b.Name, name);
        return filter;
    }
    
    public Task<MyData> GetPageByFilter(String correlationId, FilterParams filter, PagingParams paging)
    {
        return await base.GetPageByFilter(correlationId, this.ComposeFilter(filter), paging, null, null);
    }
}

var persistence = new MyPostgresPersistence();
persistence.Configure(ConfigParams.FromTuples(
    "host", "localhost",
    "port", 27017 )
);

persitence.Open("123");

persistence.Create("123", new MyData("1", "ABC"));
var mydata = persistence.GetPageByFilter(
    "123",
    FilterParams.FromTuples("name", "ABC")
);
Console.Out.WriteLine(mydata.Data);          // Result: { id: "1", name: "ABC" }

persistence.DeleteById("123", "1");