今天犯了个大错

 

public static void ChangeGoodsCounts(int GoodsID, int changCounts)        {                       int lastCount;            using (SqlConnection conn = new SqlConnection(connStr))            {                conn.Open();                using (SqlCommand cmd = conn.CreateCommand())                {                    cmd.CommandText = "select GoodsCounts from GoodsInf where GoodsID=" + GoodsID;                    int counts=Convert.ToInt32(cmd.ExecuteScalar());                    lastCount = counts + changCounts;                                       cmd.CommandText = "update GoodsInf set GoodsCounts='"+lastCount+"' where GoodsID=" + GoodsID;                    cmd.ExecuteNonQuery();                }            }        }