简单问题：如何在根据条件定位一条记录后，在保留该记录的同时，修改该记录。

Question

你先声明对应于字段的变量:
var
   field1,field2....:对应于所需的字段类型;
begin
if Locate('bianma;year;month;danjia', vararrayof([prevValue, year,month-1,strtofloat(danjia.text)]), [loCaseInsensitive])
                  then
                       field1:=query.fieldbyname('field1').text;
 .........................
query.fieldbyname('field1').text:='修改的内容';
query.append;
query.fieldbyname('field1').text:=field1;//保存刚才找到的字段数据
end;

Answer 1

var
  bianma,year,month,danja:string;
begin
  if Locate('bianma;year;month;danjia', vararrayof([prevValue, year,month-1,strtofloat(danjia.text)]), [loCaseInsensitive])
  then
  begin
    with query do
    begin
      bianma:=fieldbyname('bianma').asstring;
      year:=fieldbyname('year').asstring;
      month:=fieldbyname('month').asstring;
      danjia:=fieldbyname(('danjia').asstring;
      requestlive:=true;
      edit;
      fieldbyname('month').asinteger:=month-1;
      post;
      insert;
      fieldbyname('bianma').asstring:=bianma;
      fieldbyname('year').asstring:=year;
      fieldbyname('month').asstring:=month;
      fieldbyname('danjia').asstring:=danjia;
      post;
    end;
  end;
                      
end;