MERGE Table1 AS tgt
 USING (SELECT TOP 1 * FROM Table2,(SELECT itmid FROM Table3 WHERE id=@id) as a
        WHERE id = @id) AS src
ON (tgt.id = src.id)
            WHEN MATCHED THEN UPDATE SET qty = qty + @qty
            WHEN NOT MATCHED THEN
                INSERT itmid
                VALUES itmid;

但是当我这样改变它不工作,显示最近选择附近的错误

MERGE Table1 AS tgt
 USING (SELECT TOP 1 * FROM Table2
        WHERE id = @id) AS src
ON (tgt.id = src.id)
            WHEN MATCHED THEN UPDATE SET qty = qty + @qty
            WHEN NOT MATCHED THEN
                INSERT itmid
                SELECT itmid FROM Table3 WHERE id=@id;