Oracle cheat sheet
- SQLPlus short connection
sqlplus <username>/<password>@<ipAddress>:<port>/<sid> [@<scriptfile>]
Ex:
sqlplus user/pass@192.168.1.10:3267/MYDB @test.sql
- MySQL limit equivalent
Ex:
SELECT last_name FROM
(SELECT last_name, ROW_NUMBER() OVER (ORDER BY last_name) R FROM employees)
WHERE R BETWEEN 51 and 100;
Alternative:
select *
from ( select a.*, rownum rnum
from ( YOUR_QUERY_GOES_HERE — including the order by ) a
where rownum <= MAX_ROWS )
where rnum >= MIN_ROWS;
Linux cheat sheet
- show disk usage: du
- show disk capacity: df
- search word from file inside directory:
find /start/dir -exec grep -q my_search_word {} \; -print
- search files with specific name inside directory (HP-Unix, maxdepth=1):
find . \( ! -name . -prune \) \( -name “*TEST1*.ps” -o -name “*TEST2*.ps” \) -mtime +30 -type f
find /parent/child \( ! [...]
Simple IRIS for SBS Bus
Do you frequently travel by bus in Singapore? Do you use SBS bus? Have you ever waited for long time and the bus still hasn’t come yet? Have you ever faced situation when you needed to choose between bus or MRT but you were afraid if you chose bus you would wait for a [...]