How to Handle Variable Substitution in OPENROWSET Queries?

Variable Substitution in OPENROWSET Queries

This query encounters an error when attempting to dynamically embed a variable (@ID) into an OPENROWSET statement:

SELECT * 
FROM OPENROWSET(
    'SQLNCLI',
    'DRIVER={SQL Server};',
    'EXEC dbo.sProc1 @ID = ' + @id 
 )

The error message indicates incorrect syntax near ' ', highlighting the attempt to concatenate a string with a variable.

Why the Error Occurs

OPENROWSET does not allow for direct variable substitution. The string argument passed to the provider is evaluated verbatim, preventing the evaluation and inclusion of variables.

Solution: Dynamic SQL

To embed variables in OPENROWSET queries, you must use dynamic SQL techniques:

1. Declare the variable and initialize it with a value.
2. Construct a dynamic SQL string by concatenating the OPENROWSET statement with the variable value.
3. Prepare and execute the dynamic SQL.

Here's an example:

Declare @ID int
Declare @sql nvarchar(max)
Set @ID=1
Set @sql='SELECT * 
FROM OPENROWSET(
               ''SQLNCLI'',
               ''DRIVER={SQL Server};'',
               ''EXEC dbo.usp_SO @ID =' + convert(varchar(10),@ID) + ''')'

-- Print @sql
 Exec(@sql)

By using dynamic SQL, you can construct the provider string at runtime and dynamically include variable values.

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