各位帮忙,一个循环的问题.(100分)

我用一个query和一个table来显示数据，我从query中取值和table中的所有记录对比，
当table中已有的这条记录时越过，
当table中没有时添加一条记录到table中，我用了两个while do 来作，
with query1 do
begin
first;
while not query1.eof do
begin

with table1 do
begin
first;
while not table1.eof do
begin
if copy(table1.fieldbyname('msgtext').asstring,3,4)=copy(query1.fieldbyname('mesg').asstring,1,4) then
break//退出循环
else
next;
end;

end;
table1.append;
table1.FieldByName ('amp').asdatetime:=query1.fieldbyname('sendtime').asdatetime;
table1.FieldByName ('ori').asstring:=query1.FieldByName ('msg').asstring
table1.FieldByName ('msg').asstring:='g';
table1.FieldByName ('text').asstring:=text1+text2+text3;
table1.post;

Next ;
end;

end;
这个循环运行后是会一直在最后添加记录，我不知道应怎样才能实现这种功能。

当然会了，因为你每次都执行

table1.append;
table1.FieldByName ('amp').asdatetime:=query1.fieldbyname('sendtime').asdatetime;
table1.FieldByName ('ori').asstring:=query1.FieldByName ('msg').asstring
table1.FieldByName ('msg').asstring:='g';
table1.FieldByName ('text').asstring:=text1+text2+text3;
table1.post;

了呀。你改一下，找一个变量记录是否找到，如果找到就不要去执行这段语句了。

字段msgtext在append时没有赋值

这样写：
with query1 do
begin
first;
while not query1.eof do
begin
with table1 do
begin
first;
while not table1.eof do
begin
if copy(table1.fieldbyname('msgtext').asstring,3,4)=copy(query1.fieldbyname('mesg').asstring,1,4) then
begin
table1.append;
table1.FieldByName ('amp').asdatetime:=query1.fieldbyname('sendtime').asdatetime;
table1.FieldByName ('ori').asstring:=query1.FieldByName ('msg').asstring
table1.FieldByName ('msg').asstring:='g';
table1.FieldByName ('text').asstring:=text1+text2+text3;
table1.post;
break; //退出循环
end
else next;
end;
end;
Next ;
end;
end;

呵呵

with query1 do begin
first;
while not eof do begin
table1.first;
while not table1.eof do begin
if copy(table1.fieldbyname('msgtext').asstring,3,4)=copy(query1.fieldbyname('mesg').asstring,1,4) then begin
table1.append;
table1.FieldByName ('amp').asdatetime:=fieldbyname('sendtime').asdatetime;
table1.FieldByName ('ori').asstring:=FieldByName ('msg').asstring;
table1.FieldByName ('msg').asstring:='g';
table1.FieldByName ('text').asstring:=text1+text2+text3;
table1.post;
break; //退出循环
end else Table1.next;
end;
end;
Next ;
end;

我加了一个变量来判断，已经解决问题，多谢各位