不知道你说的是不是这样:select sum(field1-field2) as field3 from tb
var LANEL,Str:string; begin str:='select 结余=IsNull(sum(收入-支出),0) from TableName'; with Query do begin close; sql.clear; sql.add(str); Open; if RecordCount<>0 then LANEL:=fieldbyname('结余').asstring else LANEL:='0'; end; end;
错了。才看清楚。是LABEL吧。 那样的话只能是SELECT RUTURN=SUM(IN)-SUM(OUT) FROM TABLENAME GROUP BY TRUE 这样能返回一行记录。否则将返回多行记录。
THANK YOU XZISGOOD! 是我写错了,是LABEL请问如何将RUTURN的值赋给LABEL。CAPTION?
THANK YOU XZISGOOD! 是我写错了,是LABEL。补充说明表中没有节余字段只有收入和支出两字段.请问如何将RUTURN的值赋给LABEL。CAPTION?
with Query do begin close; sql.clear; sql.add(select sum=sum(收入)-sum(支出) from tablename); Open; label1.caption:=fieldbyname('sum').asstring end;
你可以这样 with Query1 do begin close; sql.clear; sql.add('select sum(收入-支出) as sum1 from tablename'); Open; label1.caption:=fieldbyname('sum1').asstring; end;
with Query1 do begin close; sql.clear; add(select sum=sum(收入)-sum(支出) from tablename); open; label1.caption:=fieldbyname('sum').asstring end
LANEL,Str:string;
begin
str:='select 结余=IsNull(sum(收入-支出),0) from TableName';
with Query do
begin
close;
sql.clear;
sql.add(str);
Open;
if RecordCount<>0 then
LANEL:=fieldbyname('结余').asstring
else LANEL:='0';
end;
end;
那样的话只能是SELECT RUTURN=SUM(IN)-SUM(OUT) FROM TABLENAME GROUP BY TRUE
这样能返回一行记录。否则将返回多行记录。
是我写错了,是LABEL请问如何将RUTURN的值赋给LABEL。CAPTION?
是我写错了,是LABEL。补充说明表中没有节余字段只有收入和支出两字段.请问如何将RUTURN的值赋给LABEL。CAPTION?
begin
close;
sql.clear;
sql.add(select sum=sum(收入)-sum(支出) from tablename);
Open;
label1.caption:=fieldbyname('sum').asstring
end;
with Query1 do
begin
close;
sql.clear;
sql.add('select sum(收入-支出) as sum1 from tablename');
Open;
label1.caption:=fieldbyname('sum1').asstring;
end;
begin
close;
sql.clear;
add(select sum=sum(收入)-sum(支出) from tablename);
open;
label1.caption:=fieldbyname('sum').asstring
end