Can SQL Server Scalar-Valued UDFs Accept Single-Column Table Parameters?

Passing Table Parameters to SQL Server UDFs

Problem:

Is it possible to pass a table as a parameter to a scaler-valued user-defined function (UDF) in SQL Server, with the restriction that the table contains only a single column?

Answer:

Yes, it is possible to pass table parameters to UDFs, provided that the data type of the table is not the timestamp data type. To achieve this, user-defined table types must be utilized.

Example of User-defined Table Type and UDF Usage:

CREATE TYPE TableType AS TABLE (LocationName VARCHAR(50))
GO

CREATE FUNCTION Example(@TableName TableType READONLY)
RETURNS VARCHAR(50)
AS
BEGIN
    DECLARE @name VARCHAR(50)
    SELECT TOP 1 @name = LocationName FROM @TableName
    RETURN @name
END
GO

DECLARE @myTable TableType
INSERT INTO @myTable(LocationName) VALUES('aaa')
SELECT * FROM @myTable

SELECT dbo.Example(@myTable)

Handling Data from a Table:

To pass a table of data from an existing table into a user-defined table type variable, the following code can be used:

DECLARE @myTable TableType
INSERT INTO @myTable(field_name)
SELECT field_name_2 FROM my_other_table

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