<s>
In	O
computing	O
,	O
a	O
data	B-General_Concept
source	I-General_Concept
name	I-General_Concept
(	O
DSN	O
,	O
sometimes	O
known	O
as	O
a	O
database	B-General_Concept
source	I-General_Concept
name	I-General_Concept
,	O
though	O
"	O
data	B-Operating_System
sources	I-Operating_System
"	O
can	O
comprise	O
other	O
repositories	O
apart	O
from	O
databases	B-Application
)	O
is	O
a	O
string	O
that	O
has	O
an	O
associated	O
data	B-General_Concept
structure	I-General_Concept
used	O
to	O
describe	O
a	O
connection	O
to	O
a	O
data	O
source	O
.	O
</s>
<s>
Most	O
commonly	O
used	O
in	O
connection	O
with	O
ODBC	B-Application
,	O
DSNs	O
also	O
exist	O
for	O
JDBC	B-Language
and	O
for	O
other	O
data	O
access	O
mechanisms	O
.	O
</s>
<s>
The	O
term	O
often	O
overlaps	O
with	O
"	O
connection	B-Language
string	I-Language
"	O
.	O
</s>
<s>
Most	O
systems	O
do	O
not	O
make	O
a	O
distinction	O
between	O
DSNs	O
or	O
connection	B-Language
strings	I-Language
and	O
the	O
term	O
can	O
often	O
be	O
used	O
interchangeably	O
.	O
</s>
<s>
Standardizing	O
DSNs	O
offers	O
a	O
level	O
of	O
indirection	O
;	O
various	O
applications	O
(	O
for	O
example	O
:	O
Apache/PHP	O
and	O
IIS/ASP	O
)	O
can	O
take	O
advantage	O
of	O
this	O
in	O
accessing	O
shared	O
data	B-Operating_System
sources	I-Operating_System
.	O
</s>
<s>
Software	O
(	O
e.g.	O
,	O
Crystal	O
Reports	O
,	O
Microsoft	O
Excel	O
,	O
PHP	B-Application
,	O
Perl	B-Language
,	O
Python	O
,	O
Ruby	O
)	O
users	O
can	O
submit	O
CRUD	O
(	O
Create	O
,	O
Read	O
,	O
Update	O
,	O
Delete	O
)	O
queries	O
to	O
a	O
data	O
source	O
by	O
establishing	O
a	O
connection	O
to	O
the	O
DSN	O
.	O
</s>
<s>
ASP	B-General_Concept
(	O
VBScript	B-Application
)	O
code	O
to	O
open	O
a	O
DSN	O
connection	O
might	O
look	O
like	O
the	O
following	O
:	O
</s>
<s>
PHP	B-Application
with	O
PDO	O
.	O
</s>
<s>
In	O
Perl	B-Language
,	O
using	O
the	O
Perl	B-Language
DBI	I-Language
module	O
,	O
each	O
driver	O
has	O
its	O
own	O
syntax	O
for	O
the	O
DSN	O
attributes	O
.	O
</s>
