Database

select field1,
field2,
field3,
field1*field2-field3 as some_alias
from table1
where (field1*field2-field3) between 10 and 20

Ashish Kumar Vyas wrote:

how to create index

Ashish Kumar Vyas wrote:

in which field it should be

Ashish Kumar Vyas wrote:

explain me this concept in example

CREATE DATABASE database_name<br />

CREATE TABLE table_name<br />
(<br />
column_name1 data_type,<br />
column_name2 data_type,<br />
.......<br />
)<br />

CREATE TABLE Person <br />
(<br />
LastName varchar,<br />
FirstName varchar,<br />
Address varchar,<br />
Age int<br />
)

CREATE TABLE Person <br />
(<br />
LastName varchar(30),<br />
FirstName varchar,<br />
Address varchar,<br />
Age int(3) <br />
)

Data Type 	Description
integer(size)
int(size)
smallint(size)
tinyint(size) 	Hold integers only. The maximum number of digits are specified in parenthesis.
decimal(size,d)
numeric(size,d) 	Hold numbers with fractions. The maximum number of digits are specified in "size". The maximum number of digits to the right of the decimal is specified in "d".
char(size) 	Holds a fixed length string (can contain letters, numbers, and special characters). The fixed size is specified in parenthesis.
varchar(size) 	Holds a variable length string (can contain letters, numbers, and special characters). The maximum size is specified in parenthesis.
date(yyyymmdd) 	Holds a date

CREATE INDEX index_name<br />
ON table_name (column_name)<br />

<br />
CREATE INDEX PersonIndex<br />
ON Person (LastName)

<br />
CREATE INDEX PersonIndex<br />
ON Person (LastName DESC)

CREATE INDEX PersonIndex<br />
ON Person (LastName, FirstName)<br />

rahul.net11 wrote:

I have solved that one