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Table.View

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Syntax

Table.View(table as nullable table, handlers as record) as table

About

Returns a view of table where the functions specified in handlers are used in lieu of the default behavior of an operation when the operation is applied to the view.

If table is provided, all handler functions are optional. If table isn't provided, the GetType and GetRows handler functions are required. If a handler function isn't specified for an operation, the default behavior of the operation is applied to table instead (except in the case of GetExpression).

Handler functions must return a value that is semantically equivalent to the result of applying the operation against table (or the resulting view in the case of GetExpression).

If a handler function raises an error, the default behavior of the operation is applied to the view.

Table.View can be used to implement folding to a data source—the translation of M queries into source-specific queries (for example, to create T-SQL statements from M queries).

Refer to the published Power Query custom connector documentation for a more complete description of Table.View.

Example 1

Create a basic view that doesn't require accessing the rows in order to determine the type or the row count.

Usage

Table.View(
    null,
    [
        GetType = () => type table [CustomerID = number, Name = text, Phone = nullable text],
        GetRows = () => Table.FromRecords({[CustomerID = 1, Name = "Bob", Phone = "123-4567"]}),
        GetRowCount = () => 1
    ]
)

Output

Table.FromRecords({[CustomerID = 1, Name = "Bob", Phone = "123-4567"]})