Data Types:-
Data types are a classification of a particular type of
information. It is easy for humans to distinguish between different types of
data. SQL supports following data types:
1)Character(n)
This data type represents a fixed length string of exactly 'n'
characters where 'n'is greater than zero and should be an integer.
Example:-
Name character(10)
or
Name char(10)
2) Varchar(n) or character varying(n)
This data type represents a varying length string
whose maximum length is 'n' characters.
Example:-
Name varchar(n)
3) Numeric (p,q)
This data type represent a decimal number 'p'
digits and sign with assumed decimal point 'q' digits from the sign. Both 'p'
and 'q' are integers.
Example:-
Price numeric(6,2)
4)Integer
An integer represents a signed integer decimal or
binary.
Example:-
Roll_No integer(3)
5) Small int
A small integer is a machine independent subset of
the integer domain type
Example:-
Roll_No small int(3)
6) Real, double precision
Floating point and double-precision floating point numbers
with machine dependent precision.
7) Float(n)
A floating point number, with precision of at least n
digits.
Example:-
Rate float(5,2)
8) Date
A calendar date containing a (four-digit) year, month
and day of the month
Example:-
Date_of_birth date
9) Time
The time of day, in hours, minutes and seconds. A
variant, time(p) can be used to specify the number of fractional digits for
seconds (the default being 0)
Example:-
Arrival_time time
10) Time stamp
A combination of date and time. A variant, timestamp
(P), can be used to specify the number of fractional digits for seconds.
Date and time values can be specified like this:
date '2005-04-25'
time '09:10:25'
time stamp '2005-04-25 08:25:30.45'
Dates must be specified in the format-year followed by
month followed by day, as shown. The seconds field of time or timestamp can
have a fractional part, as in the timestamp above
No comments:
Post a Comment