fix(mssql): attempt to support MERGE for backend

Author: deepyaman

ibis/backends/mssql/__init__.py

@@ -441,6 +441,8 @@ def raw_sql(self, query: str | sg.Expression, **kwargs: Any) -> Any:
         with contextlib.suppress(AttributeError):
             query = query.sql(self.dialect)
 
+        query = f"{query};"
+
         con = self.con
         cursor = con.cursor()