Oracle SQL - 如何显示 2 个小数位

Question

Just help me out to display a number whose length is unknown with 2 decimal places. Example: If the number is 230000 then i need it to be printed as 230000.00

I tried

Select to_char(amount, 'FM99999999.90') as amt from customer;

Answer 1

Formatting is usually front-end "problem"; every decent tool (be it Oracle Apex, Reports, Forms, Jasper Reports, ...) has an option to format a number as you want it. Why? So that those values remain numbers , to be able to apply eg SUM function to them or whatever you may need.

In SQL*Plus (or similar, even GUI tools), formatting is done by the TO_CHAR function and desired format mask. If you want two decimals and (just for example) thousands separator, you might do something like this:

SQL> with customer (amount) as
  2    (select 230000 from dual union all
  3     select 3.14   from dual union all
  4     select 0.0002 from dual union all
  5     select 25.123 from dual
  6    )
  7  select amount,
  8         to_char(amount, 'fm999g999g990d00') new_amount,
  9    lpad(to_char(amount, 'fm999g999g990d00'), 10, ' ') new_amount2
 10  from customer;

    AMOUNT NEW_AMOUNT      NEW_AMOUNT2
---------- --------------- ----------------------------------------
    230000 230.000,00      230.000,00
      3,14 3,14                  3,14
     ,0002 0,00                  0,00
    25,123 25,12                25,12

SQL>

• note that new values have... 0d00 format mask which makes sure you'll actually see zeroes around the decimal point.
• use G and D for thousand groups and decimals, rather than commas and dots
• new_amount2 , aditionaly, has lpad applied so that values are right-aligned. I presumed that max length of those values is 10 (you'd know better)

---

If you do use SQL*Plus (which is quite rare nowadays), you could even use its set numformat command so - no additional modifications are necessary; you just select what you have:

SQL> set numformat 999g990d00
SQL>
SQL> with customer (amount) as
  2    (select 230000 from dual union all
  3     select 3.14   from dual union all
  4     select 0.0002 from dual union all
  5     select 25.123 from dual
  6    )
  7  select amount
  8  from customer;

     AMOUNT
-----------
 230.000,00
       3,14
       0,00
      25,12

SQL>

Answer 2

Use concat as follows:

select concat(amount, '.00') from customer