Hi there,
You should use a 'N' prefix.
This denotes that the subsequent string is in Unicode (the N actually stands for National language character set). Which means that you are passing an NCHAR, NVARCHAR or NTEXT value, as opposed to CHAR, VARCHAR or TEXT.
for example:
INSERT INTO ... VALUES (N'String',N'String';...
UPDATE ... SET ...=N'String'...WHERE ...=N'String'
SELECT ... FROM ... WHERE ...=N'String'.