Calculate the difference between two rows from two different tables

Question

I have two tables with structures below

table one

╔════╦═══════════╦═══════╦══╗
║ ID ║ Date ║ value ║ ║
╠════╬═══════════╬═══════╬══╣
║ 1 ║ 1/1/2015 ║ 234 ║ ║
║ 2 ║ 1/20/2015 ║ 267 ║ ║
║ 3 ║ 1/25/2015 ║ 270 ║ ║
╚════╩═══════════╩═══════╩══╝

second table

╔════════════════════════╗
║ start_date ║ end date ║
╠════════════════════════╣
║ 1/1/2015 ║ 1/20/2015 ║
║ 1/20/2015 ║ 1/25/2015 ║
╚════════════════════════╝

My conclusion should be

╔════════════════════════╦════════════╗
║ start_date ║ end date ║ difference ║
╠════════════════════════╬════════════╣
║ 1/1/2015 ║ 1/20/2015 ║ 33 ║
║ 1/20/2015 ║ 1/25/2015 ║ 3 ║
╚════════════════════════╩════════════╝

, , ( ) , sql.

, .

,

select start_date, end_date, ((SELECT
                    table_one.value
                FROM
                    table_one, 
                    table_two 
                WHERE 
                    table_one.date= table_two.end_date(+)
                ) - (
                SELECT
                    table_one.value
                FROM
                    table_one, 
                    table_two 
                WHERE 
                    table_one.date = table_two.start_date(+)
                ))from table_two,table_one where table_two.start_date(+)=table_one.date

ORA-01427 . ?

Answer 1

join s:

select t2.start_date, t2.end_date, (t1e.value - t1s.value) as difference
from table2 t2 join
     table1 t1s
     on t2.start_date = t1s.date join
     table1 t1e
     on t2.end_date = t1e.date;

table2 table1, left join .