Oracle中to_number()函数的学习

Converts a string to the NUMBER data type（将字符串转换为数字数据类型）
TO_NUMBER(<value>[, <format>, <NLS parameter>]) RETURN NUMBER
select   to_number('00001228')   from   dual; 
to_number('00001228')
                1228 
select   trunc(to_number('123.123'),2)   from   dual;

Converts a HEX number to FLOAT（转换一个十六进制数的浮标）
TO_NUMBER(<value>, <format>);
SELECT TO_NUMBER('0A', 'XX')
FROM dual;

Converts a HEX number to DECIMAL（一个十六进制数转换为十进制）
TO_NUMBER(<binary_float | binary_double | number>,
'<hex mask>') RETURN <binary_float | binary_double | number>;
SELECT TO_NUMBER(100000,'XXXXXXXX')
FROM dual;