I have a stored procedure with an nvarchar parameter. I expect callers to supply the text for a sql command when using this SP.
How do I execute the supplied sql command from within the SP?
Is this even possible?-
I thought it was possible using EXEC but the following:
EXEC @script
errors indicating it can't find a stored pr开发者_C百科ocedure by the given name. Since it's a script this is obviously accurate, but leads me to think it's not working as expected.
Use:
BEGIN
EXEC sp_executesql @nvarchar_parameter
END
...assuming the parameter is an entire SQL query. If not:
DECLARE @SQL NVARCHAR(4000)
SET @SQL = 'SELECT ...' + @nvarchar_parameter
BEGIN
EXEC sp_executesql @SQL
END
Be aware of SQL Injection attacks, and I highly recommend reading The curse and blessing of Dynamic SQL.
you can just exec @sqlStatement from within your sp. Though, its not the best thing to do because it opens you up to sql injection. You can see an example here
You use EXECUTE
passing it the command as a string. Note this could open your system up to serious vulnerabilities given that it is difficult to verify the non-maliciousness of the SQL statements you are blindly executing.
How do I execute the supplied sql command from within the SP?
Very carefully. That code could do anything, including add or delete records, or even whole tables or databases.
To be safe about this, you need to create a separate user account that only has dbreader permissions on just a small set of allowed tables/views and use the EXECUTE AS command to limit the context to that user.
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