SQL Where

The WHERE clause is used to extract only those records that fulfill a specified criterion.

SQL WHERE Syntax

SELECT column_name(s)
FROM table_name
WHERE column_name operator value

Table Name : CustMast

custcode	custname	city	qty	rate
1	Siva	Srivilliputtur	50	70
2	Bala	Sivakasi	30	56
3	Kanna	Madurai	100	200
4	Vijay	Chennai	30	30
5	Kodee	Srivilliputtur	60	30
5	Kodee	Srivilliputtur	60	30

                                                         
                                                         For TEXT  values:

Ex: 1

Select CustName,City from CustMast where Custname='Siva'

OutPut :

custname	city
Siva	Srivilliputtur

Ex: 2

Wrong Below Coding

Select CustName,City from CustMast where Custname=Siva

Error : Invalid column name 'siva'.

Note: ( SQL uses single quotes around text values (most database systems will also accept double quotes).

Although, numeric values should not be enclosed in quotes.)

                                                   For NUMERIC  values:

This is correct:

SELECT * FROM Persons WHERE Year=1965

This is wrong:

SELECT * FROM Persons WHERE Year='1965'

Operators Allowed in the WHERE Clause

With the WHERE clause, the following operators can be used:

Operator	Description
=	Equal
<>	Not equal
>	Greater then
<	Less than
>=	Greater than or equal
<=	Less than or equal
BETWEEN	Between an inclusive range
LIKE	Search for a pattern
IN	If you know the exact value you want to return for at least one of the columns

Note: In some versions of SQL the <> operator may be written as !=