February 9, 2015

SQL Select Query Examples-retrieve Last five records,subquery , last letters in capital

Select Query to retrieve Last five records of the table

select * from emp a where 5 >= (select count(1) from emp b where a.empno != b.empno and a.sal <= b.sal)
order by a.sal desc

assumptions:
1. Empno is primary key in emp table
2. 5 last records must be required based on some sorting, so i took it as salary.

Select Query to get the first and last letters in capital in SQL

This is sample example to use Select Query to get the first and last letters in capital in SQL.

You can use with your table instead of test5. upper is function to get letter in upper case and substr method is used to get first and last letter.

select upper(substr(ename,1,1)) || substr(ename,2,length(ename)-2) || upper(substr(ename,length
(ename),1)) from test5;

Example of subquery in sql

select e.employee_id,e.first_name||' '||last_name as name,e.department_id,e.hire_date,e.manager_id,d.department_name,
m.first_name||' '||m.last_name manager from employees e join departments d
on e.department_id=d.department_id left outer join emp m
on e.manager_id=m.employee_id
where d.department_name=initcap('shipping') order by e.employee_id;

Select query to get range of Records:

To get range of records in sql you can try following select query. In this query num1 and num2 is a query parameters. Using minus will filter records  from first table. It will show non common  rows from tables.

select * from table_name where rowid in (select rowid from table_name
where rownum < &num1 minus select rowid from table_name
where rownum < &num2