String sql="insert into Employees(empid,empname,sex,id_card,nation,nationality,family_place,birthaddress,birthdate,age,mari_cond,sold_cond,sold_date";
                                sql+=",reti_date,live_addr,mailcode,phone,street,hukou,bel_street,quality,for_iden,habi_date,vehicle,edsource)";
                                sql+=" values('"+this.empid.Text+"','"+this.empname.Text+"','"+this.sex.Text+"','"+this.id_card.Text+"','"+this.nation.Text+"','"+this.nationality.Text+"','";
                                sql+=this.family_place.Text+"','"+this.birthaddress.Text+"','"+to_date(this.birthdate.Text,'yyyy-mm-dd')+"','"+this.age.Text+"','"+this.mari_cond.Text+"','"+this.sold_cond.Text+"',";
                                sql+=to_date(this.sold_date.Text,'yyyy-mm-dd')+",'"+to_date(this.reti_date.Text,'yyyy-mm-dd')+"','"+this.live_addr.Text+"','"+this.mailcode.Text+"','"+this.phone.Text+"','"+this.street.Text+"','";
                                sql+=this.hukou.Text+"','"+this.bel_street.Text+"','"+this.quality.Text+"','"+this.for_iden.Text+"','"+to_date(this.habi_date.Text,'yyyy-mm-dd')+"','"+this.vehicle.Text+"','"+this.edsource.Text+"')";

然后程序编译错误 说 字符文本中字符太多. 我估计是to_date里面可能可能引号标的有问题.请教具体怎么改呀?