IdentifiableJsonPostgresPersistence

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

Implements: IdentifiablePostgresPersistence,

Description

The IdentifiableJsonPostgresPersistence class allows you to create persistence components used to store data in PosgreSQL databases in JSON or JSONB fields 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) PostgreSQL collection name

  • connection(s):

    • discovery_key: (optional) key used 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

Creates a new instance of the persistence component.

InheritIdentifiableJsonPostgresPersistence[T any, K any](overrides IPostgresPersistenceOverrides[T], tableName string) *IdentifiableJsonPostgresPersistence[T, K]

Methods

ConvertFromPublic

Converts object value from public to internal format.

(c *IdentifiableJsonPostgresPersistence[T,K]) ConvertFromPublic(value T) map[string]any

  • value: T - object in public format to convert.
  • returns: map[string]any - converted object in internal format.

ConvertToPublic

Converts object value from internal to public format.

(c *IdentifiableJsonPostgresPersistence[T,K]) ConvertToPublic(rows pgx.Rows) T

  • rows: pgx.Rows - object in internal format to convert.
  • returns: T - converted object in public format.

EnsureTable

Adds DML statement to automatically create a JSON(B) table

(c *IdentifiableJsonPostgresPersistence[T,K]) EnsureTable(idType string, dataType string)

  • idType: string - type of the id column
  • dataType: string - type of the data column

UpdatePartially

Updates only few selected fields in a data item.

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

  • ctx: context.Context - operation context.
  • context: IContext - (optional) a context to trace execution through a call chain.
  • id: interface{} - id of the data item to be updated.
  • data: *cdata.AnyValueMap - map with fields to be updated.
  • return: (result interface{}, err error) - updated item

Examples

type DummyJsonPostgresPersistence struct {
	*persist.IdentifiableJsonPostgresPersistence[fixtures.Dummy, string]
}

func NewDummyJsonPostgresPersistence() *DummyJsonPostgresPersistence {
	c := &DummyJsonPostgresPersistence{}
	c.IdentifiableJsonPostgresPersistence = persist.InheritIdentifiableJsonPostgresPersistence[fixtures.Dummy, string](c, "dummies_json")
	return c
}

func (c *DummyJsonPostgresPersistence) DefineSchema() {
	c.ClearSchema()
	c.IdentifiableJsonPostgresPersistence.DefineSchema()
	c.EnsureTable("", "")
	c.EnsureIndex(c.TableName+"_key", map[string]string{"(data->'key')": "1"}, map[string]string{"unique": "true"})
}

func (c *DummyJsonPostgresPersistence) 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 += "data->key='" + key + "'"
	}

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

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

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

	return c.IdentifiableJsonPostgresPersistence.GetCountByFilter(ctx, context, filterObj)
}

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