Oracle-案例说明

Question

Hello – I am seeking your help with the below case statement but I am not sure how to change it accordingly. Could you please help? New to SQL but learning.

This is what is required

When sales_number start with zero/s then remove leading zeros so the sales_number is a total of 14 characters Then concatenate sales_number (14 digits) and sales_date and sales_amount When the sales_number is less than 16 characters Then concatenate the last nine characters from sales_number and sales_date and sales_amount

This is my attempt to create the case statement

CASE
when length(to_char(remove leading zeros from sales_number)) = 14
then to_char(sales_number without leading zeros)) || sales_date ||sales_amount
when  sales_number < 16
then right(to_char(last nine characters from sales_number and sales_date and sales_amount)

Many Thanks.

Answer 1

Maybe this can give on idea on what you need;

with test(sales_number, sales_date, sales_amount) as 
(
select '001245JNF690864350', sysdate, 100 from dual union all
select 'SD895394KK9746K0000334', sysdate, 100 from dual union all
select '3850956789025417', sysdate, 100 from dual
)
select case
        when regexp_like(sales_number, '^0{1,}') /* starts with one or more zeros */ 
            then ltrim(sales_number, '0') /* remove leading zeros */
                 || sales_date ||sales_amount
        when length(sales_number) = 16
            then substr(sales_number, -9) /* last 9 chars */
                 || sales_date ||sales_amount
        else
            '' /* what to do here? */ 
    end
from test

It's not that clear to me what to do when none of your conditions is matched, so i left it blank; hope this can help to find your solution