Type.TablePartitionKey
TypeReturns the partition key for the given table type, if one is defined.
Syntax
Type.TablePartitionKey(tableType as type) as nullable listParameters
| Name | Type | Required | Description |
|---|---|---|---|
tableType | type | Yes | The table type whose partition key to retrieve. |
Return Value
list — A list of column names that form the partition key of the table type, or null if no partition key is defined.
Remarks
Type.TablePartitionKey returns the partition key metadata attached to a table type as a list of column names, or null if no partition key has been defined on the type.
This is the type-system counterpart to Table.PartitionKey. While Table.PartitionKey retrieves partition key metadata from a table value, Type.TablePartitionKey retrieves it from a table type definition.
### Use cases
- Inspecting table type metadata in custom connector development.
- Verifying that a table type has the expected partition key before using it.
- Working with the Power Query SDK to read partitioned data source type definitions.
Partition keys indicate how a table's data is logically segmented. They are primarily relevant when working with partitioned data sources or building custom connectors that expose partitioned data to the Power Query engine for parallel evaluation.
Examples
Example 1: Check the partition key of a table type
let
MyType = Type.ReplaceTablePartitionKey(
type table [Region = text, Sales = number],
{"Region"}
),
Key = Type.TablePartitionKey(MyType)
in
if Key = null then "No partition key" else Text.Combine(Key, ", ")