有一表a
字段为a1,a2,a3,a4
10 19 5 6
5 5 7 8我要将a1+a2-a3-a4赋给a5
select a1,a2,a3,a4,a1+a2-a3-a4 as a5 from a
结果怎么乱七八糟的
注:我的a1,a2,a3,a4都是字符型字段。
字段为a1,a2,a3,a4
10 19 5 6
5 5 7 8我要将a1+a2-a3-a4赋给a5
select a1,a2,a3,a4,a1+a2-a3-a4 as a5 from a
结果怎么乱七八糟的
注:我的a1,a2,a3,a4都是字符型字段。
在select语句中好象没关系的。
用cast 或convert
select a1,a2,a3,a4,cast(a1 as int)+cast(a2 as int)- cast(a3 as int)-cast(a4 as int) as a5 from a
select a1,a2,a3,a4,cast(a1 as int)+a2-a3-a4 as a5 from a
还有一种类型转化
select a1,a2,a3,a4,convert(int,a1)+a2-a3-a4 as a5 from a
如果是在delphi中呢!(如果是在Access中!)
添加一个计算字段:
在计算事件中 FieldByName(a1).asintger+FieldByName(a2).asintger-FieldByName(a3).asintger-FieldByName(a4).asintger
正确答案:
select cint(a1)+cint(a2)-cint(a3)-cint(a4) from a但不知实数是怎么处理的????????
select a1,a2,a3,a4,to_NUMBER(a1+a2-a3-a4) from a
OK 了
select a1,a2,a3,a4,convert(int,a1)+convert(int,a2)+convert(int,a3)+convert(int,a4) as a5from a
convert和cast
select cint(a1)+cint(a2)-cint(a3)-cint(a4) from a
怎么样字符转成实数型?
cfloat(a1)出错!!!!!!!!!!!!!!!!!!!!!!!!
select a1,a2,a3,a4,convert(int,a1)+convert(int,a2)+convert(int,a3)+convert(int,a4) as a5from a