SQL oracle中的正值负值和负值正值
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Positive value to negative and negative to positive in oracle
提问by Pravin Satav
I have a requirement to convert postive value to negative and negative to positive and if its 0 then leave as it is. Im able to do it in sql, just need to know if there is any better way/alternate way to do it?
我需要将正值转换为负值，将负值转换为正值，如果为 0，则保持原样。我可以在 sql 中做到这一点，只需要知道是否有更好的方法/替代方法来做到这一点？
create table test_tab
(a number);
insert into test_tab values (10);
insert into test_tab values (-10);
insert into test_tab values (0);
insert into test_tab values (10.15);
insert into test_tab values (-10.15);
select a , decode(sign(a),-1,abs(a),1,-abs(a),0) "changed value" from test_tab;
Database Oracle - 11g
数据库 Oracle - 11g
回答by Alen Oblak
What about multiplying with -1 ?
乘以 -1 怎么样？
select a
, -1 * a "changed value"
from test_tab;
回答by vhadalgi
how about just putting a negative sign
只加一个负号怎么样
SELECT - -15 as inverse;
-->15
SELECT -15 as inverse;
-->-15
回答by Dalton Bohning
How about using subtraction:
如何使用减法：
SELECT 0 - a "changed value"
from test_tab;
回答by vasin1987
select a , decode(sign(a),-1,abs(a),1,-abs(a),0) -a from test_tab;
that's all you need
这就是你所需要的
