IdentifiablePostgresPersistence

Abstract persistence component that stores data in PostgreSQL and implements a number of CRUD operations over data items with unique ids.

Implements: 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 c.Db or c.Collection 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:

  • connect_timeout: (optional) number of milliseconds to wait before timing out when connecting a new client (default: 0)
  • idle_timeout: (optional) number of milliseconds a client must sit idle in the pool and not be checked out (default: 10000)
  • max_pool_size: (optional) maximum number of clients the pool can contain (default: 10)

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

InheritIdentifiablePostgresPersistence

Creates a new instance of the persistence component.

InheritIdentifiablePostgresPersistence[T any, K any](overrides IPostgresPersistenceOverrides[T], tableName string) *IdentifiablePostgresPersistence[T,K]

Methods

Create

Creates a data item.

(c *IdentifiablePostgresPersistence[T,K]) Create(ctx context.Context, context IContext, item T) (result T, err error)

  • ctx: context.Context - operation context.
  • context: IContext - (optional) a context to trace execution through a call chain.
  • item: T - item to be created.
  • returns: (result T, err error) - created item

DeleteById

Deletes a data item by it’s unique id.

(c *IdentifiablePostgresPersistence[T,K]) DeleteById(ctx context.Context, context IContext, id K) (result T, err error)

  • ctx: context.Context - operation context.
  • context: IContext - (optional) a context to trace execution through a call chain.
  • id: K - id of the item to be deleted
  • returns: (result T, err error) - deleted item

DeleteByIds

Deletes multiple data items by their unique ids.

(c *IdentifiablePostgresPersistence[T,K]) DeleteByIds(ctx context.Context, context IContext, ids []K) error

  • ctx: context.Context - operation context.
  • context: IContext - (optional) a context to trace execution through a call chain.
  • ids: []K - ids of data items to be deleted.
  • returns: error - returns error if not received.

GetListByIds

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

(c *IdentifiablePostgresPersistence[T,K]) GetListByIds(ctx context.Context, context IContext, ids []K) (items []T, err error)

  • ctx: context.Context - operation context.
  • context: IContext - (optional) a context to trace execution through a call chain.
  • ids: []K - ids of data items to be retrieved
  • returns: (items []T, err error) - data list

GetOneById

Gets a data item by its unique id.

(c *IdentifiablePostgresPersistence[T,K]) GetOneById(ctx context.Context, context IContext, id K) (item T, err error)

  • ctx: context.Context - operation context.
  • context: IContext - (optional) a context to trace execution through a call chain.
  • id: K - id of data item to be retrieved.
  • returns: (item T, err error) - data item

Set

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

(c *IdentifiablePostgresPersistence[T,K]) Set(ctx context.Context, context IContext, item T) (result T, err error)

  • ctx: context.Context - operation context.
  • context: IContext - (optional) a context to trace execution through a call chain.
  • item: T - item to be set.
  • returns: (result T, err error) - updated item

Update

Updates a data item.

(c *IdentifiablePostgresPersistence[T,K]) Update(ctx context.Context, context IContext, item interface{}) (result T, err error)

  • context: IContext - (optional) a context to trace execution through a call chain.
  • item: T - item to be updated.
  • returns: (result T, err error) - updated item

UpdatePartially

Updates only a few selected fields in a data item.

(c *IdentifiablePostgresPersistence[T,K]) UpdatePartially(ctx context.Context, context IContext, id K, data *cdata.AnyValueMap) (result T, err error)

  • context: IContext - (optional) a context to trace execution through a call chain.
  • id: K - id of the data item to be updated.
  • data: *cdata.AnyValueMap - map with fields to be updated.
  • returns: (result T, err error)- updated item

Examples

type DummyPostgresPersistence struct {
	*persist.IdentifiablePostgresPersistence[fixtures.Dummy, string]
}

func NewDummyPostgresPersistence() *DummyPostgresPersistence {
	c := &DummyPostgresPersistence{}
	c.IdentifiablePostgresPersistence = persist.InheritIdentifiablePostgresPersistence[fixtures.Dummy, string](c, "dummies")
	return c
}

func (c *DummyPostgresPersistence) DefineSchema() {
	c.ClearSchema()
	c.IdentifiablePostgresPersistence.DefineSchema()
	// Row name must be in double quotes for properly case!!!
	c.EnsureSchema("CREATE TABLE " + c.QuotedTableName() + " (\"id\" TEXT PRIMARY KEY, \"key\" TEXT, \"content\" TEXT)")
	c.EnsureIndex(c.IdentifiablePostgresPersistence.TableName+"_key", map[string]string{"key": "1"}, map[string]string{"unique": "true"})
}

func (c *DummyPostgresPersistence) GetPageByFilter(ctx context.Context, context IContext,
	filter cdata.FilterParams, paging cdata.PagingParams) (page cdata.DataPage[fixtures.Dummy], err error) {

	key, ok := filter.GetAsNullableString("Key")
	filterObj := ""
	if ok && key != "" {
		filterObj += "key='" + key + "'"
	}
	sorting := ""

	return c.IdentifiablePostgresPersistence.GetPageByFilter(ctx, context,
		filterObj, paging,
		sorting, "",
	)
}

func (c *DummyPostgresPersistence) GetCountByFilter(ctx context.Context, context IContext,
	filter cdata.FilterParams) (count int64, err error) {

	key, ok := filter.GetAsNullableString("Key")
	filterObj := ""
	if ok && key != "" {
		filterObj += "key='" + key + "'"
	}
	return c.IdentifiablePostgresPersistence.GetCountByFilter(ctx, context, filterObj)
}

func (c *DummyPostgresPersistence) GetOneRandom(ctx context.Context, context IContext) (item fixtures.Dummy, err error) {
	return c.IdentifiablePostgresPersistence.GetOneRandom(ctx, context, "")
}