Msg 2389, Level 16, State 1, Line 7
%s’%ls’ requires a singleton (or empty sequence), found operand of type ‘%ls’
This error message appears when in an XQuery an operand is used in the wrong way.
The T-SQL statement can be parsed, but causes the error at runtime.
Errors of the Severity level 16 are generated by the user and can be fixed by the SQL Server user. The statement cannot be run this way. Operands must always be used correctly.
This error message was introduced with SQL Server 2005.
DECLARE @xml xml;
SET @xml = ‘<Result />’;
@xml.query (‘for $a in(1, 2), $b in(3, 4)
$a < $b
return sum($a + $b + c)’) as XML;
In the above example we try to use the ‘+’ operand in the expression $a + $b + c. Because c is not know in this context, the expression + c is invalid and the error is raised.