declaration.md

Dataform Javascript API Reference › Globals › "core/actions/declaration" › Declaration

Class: Declaration

You can declare any BigQuery table as a data source in Dataform. Declaring BigQuery data sources that are external to Dataform lets you treat those data sources as Dataform objects.

Declaring data sources is optional, but can be useful when you want to do the following:

• Reference or resolve declared sources in the same way as any other table in Dataform.
• View declared sources in the visualized Dataform graph.
• Use Dataform to manage the table-level and column-level descriptions of externally created tables.
• Trigger workflow invocations that include all the dependents of an external data source.

You can create declarations in the following ways. Available config options are defined in DeclarationConfig, and are shared across all the followiing ways of creating declarations.

Using a SQLX file:

-- definitions/name.sqlx
config {
  type: "declaration"
}
-- Note: no SQL should be present.

Using action configs files:

# definitions/actions.yaml
actions:
- declare:
  name: name

Using the Javascript API:

// definitions/file.js
declare("name")

Hierarchy

• ActionBuilder‹Declaration›

  ↳ Declaration

Index

Methods

• columns
• description

Methods

columns

▸ columns(columns: ColumnDescriptor[]): this

deprecated Deprecated in favor of DeclarationConfig.columns.

Sets the column descriptors of columns in this table.

Parameters:

Name	Type
columns	ColumnDescriptor[]

Returns: this

---

description

▸ description(description: string): this

deprecated Deprecated in favor of DeclarationConfig.description.

Sets the description of this assertion.

Parameters:

Name	Type
description	string

Returns: this