oracle varchar到数字

Question

如何将oracle varchar值转换为数字

例如

table - exception
exception_value 555 where exception_value is a varchar type

我想测试exception_value列的值

select * from exception where exception_value = 105 instead of
select * from exception where exception_value = '105'

Answer 1

您必须使用TO_NUMBER功能：

select * from exception where exception_value = to_number('105')

Answer 2

由于列的类型为VARCHAR，因此应将输入参数转换为字符串，而不是将列值转换为数字：

select * from exception where exception_value = to_char(105);

Answer 3

如果您想要格式化数字，请使用

SELECT TO_CHAR(number, 'fmt')
   FROM DUAL;

SELECT TO_CHAR('123', 999.99)
   FROM DUAL;

结果 123.00

Answer 4

我测试了建议的解决方案，它们都应该有效：

select * from dual where (105 = to_number('105'))

=＆GT;提供一个虚拟行

select * from dual where (10 = to_number('105'))

=＆GT;空结果

select * from dual where ('105' = to_char(105))

=＆GT;提供一个虚拟行

select * from dual where ('105' = to_char(10))

=＆GT;空结果

Answer 5

从异常中选择to_number（exception_value），其中to_number（exception_value）= 105