<s>
NHibernate	B-Language
is	O
an	O
object	B-General_Concept
–	I-General_Concept
relational	I-General_Concept
mapping	I-General_Concept
(	O
ORM	O
)	O
solution	O
for	O
the	O
Microsoft	B-Application
.NET	I-Application
platform	O
.	O
</s>
<s>
It	O
provides	O
a	O
framework	B-Architecture
for	O
mapping	O
an	O
object-oriented	B-Language
domain	B-Application
model	I-Application
to	O
a	O
traditional	O
relational	B-Application
database	I-Application
.	O
</s>
<s>
Its	O
purpose	O
is	O
to	O
relieve	O
the	O
developer	O
from	O
a	O
significant	O
portion	O
of	O
relational	O
data	O
persistence-related	O
programming	O
tasks	O
.	O
</s>
<s>
NHibernate	B-Language
is	O
free	B-License
and	I-License
open-source	I-License
software	I-License
that	O
is	O
distributed	O
under	O
the	O
GNU	B-Application
Lesser	I-Application
General	I-Application
Public	I-Application
License	I-Application
.	O
</s>
<s>
NHibernate	B-Language
is	O
a	O
port	O
of	O
Hibernate	B-Library
.	O
</s>
<s>
NHibernate	B-Language
's	O
primary	O
feature	O
is	O
mapping	O
from	O
.NET	B-Application
classes	O
to	O
database	O
tables	O
(	O
and	O
from	O
CLR	O
data	O
types	O
to	O
SQL	B-Language
data	O
types	O
)	O
.	O
</s>
<s>
NHibernate	B-Language
also	O
provides	O
data	O
query	O
and	O
retrieval	O
tools	O
.	O
</s>
<s>
It	O
generates	O
the	O
SQL	B-Language
commands	O
and	O
removes	O
the	O
need	O
manual	O
data	O
set	O
handling	O
and	O
object	O
conversion	O
,	O
keeping	O
the	O
application	O
portable	O
to	O
most	O
SQL	B-Language
databases	I-Language
,	O
with	O
database	O
portability	O
delivered	O
at	O
very	O
little	O
performance	O
overhead	O
.	O
</s>
<s>
NHibernate	B-Language
provides	O
transparent	O
persistence	B-Application
for	O
Plain	B-Language
Old	I-Language
CLR	I-Language
Objects	I-Language
(	O
POCOs	O
)	O
.	O
</s>
<s>
Tom	O
Barrett	O
started	O
NHibernate	B-Language
,	O
and	O
later	O
picked	O
up	O
by	O
Mike	O
Doerfler	O
and	O
Peter	O
Smulovics	O
.	O
</s>
<s>
At	O
the	O
end	O
of	O
2005	O
,	O
JBoss	O
,	O
Inc	O
.	O
(	O
now	O
part	O
of	O
Red	O
Hat	O
)	O
hired	O
Sergey	O
Koshcheyev	O
,	O
the	O
then	O
lead	O
developer	O
of	O
NHibernate	B-Language
,	O
to	O
work	O
full-time	O
on	O
its	O
future	O
versions	O
.	O
</s>
<s>
NHibernate	B-Language
is	O
now	O
entirely	O
developed	O
and	O
led	O
by	O
the	O
community	O
.	O
</s>
<s>
Version	O
1.0	O
mirrored	O
the	O
feature	O
set	O
of	O
Hibernate	B-Library
2.1	O
,	O
as	O
well	O
as	O
a	O
number	O
of	O
features	O
from	O
Hibernate	B-Library
3	O
.	O
</s>
<s>
NHibernate	B-Language
1.2.1	O
,	O
released	O
in	O
November	O
2007	O
,	O
introduced	O
many	O
more	O
features	O
from	O
Hibernate	B-Library
3	O
and	O
support	O
for	O
.NET	B-Application
2.0	O
,	O
stored	B-General_Concept
procedures	I-General_Concept
,	O
generics	O
,	O
and	O
nullable	O
types	O
.	O
</s>
<s>
NHibernate	B-Language
2.0	O
was	O
released	O
on	O
August	O
23	O
,	O
2008	O
.	O
</s>
<s>
It	O
is	O
comparable	O
to	O
Hibernate	B-Library
3.2	O
in	O
terms	O
of	O
features	O
.	O
</s>
<s>
With	O
the	O
version	O
2.0	O
release	O
,	O
NHibernate	B-Language
dropped	O
support	O
for	O
.NET	B-Application
1.1	O
.	O
</s>
<s>
NHibernate	B-Language
2.1	O
was	O
released	O
July	O
17	O
,	O
2009	O
.	O
</s>
<s>
NHibernate	B-Language
3.0	O
was	O
released	O
on	O
December	O
4	O
,	O
2010	O
,	O
and	O
is	O
the	O
first	O
version	O
to	O
use	O
.NET	B-Application
3.5	O
,	O
with	O
features	O
such	O
as	O
:	O
</s>
<s>
NHibernate	B-Language
3.2	O
was	O
released	O
in	O
April	O
,	O
2011	O
.	O
</s>
<s>
Subselect	O
:	O
ability	O
to	O
map	O
SQL	B-Language
views	O
as	O
entities	O
;	O
</s>
<s>
NHibernate	B-Language
4.0	O
was	O
released	O
on	O
August	O
17	O
,	O
2014	O
.	O
</s>
<s>
This	O
version	O
requires	O
.NET	B-Application
Framework	I-Application
4.0	O
or	O
later	O
.	O
</s>
<s>
NHibernate	B-Language
5.0	O
was	O
released	O
on	O
October	O
10	O
,	O
2017	O
.	O
</s>
<s>
This	O
version	O
requires	O
.NET	B-Application
Framework	I-Application
4.6.1	O
or	O
later	O
.	O
</s>
<s>
NHibernate	B-Language
5.1	O
was	O
released	O
on	O
March	O
17	O
,	O
2018	O
.	O
</s>
<s>
It	O
supports	O
.NET	B-Application
Standard	O
2.0	O
and	O
.NET	B-Application
Core	I-Application
2.0	I-Application
.	O
</s>
<s>
NHibernate	B-Language
5.2	O
was	O
released	O
on	O
December	O
4	O
,	O
2018	O
.	O
</s>
<s>
NHibernate	B-Language
5.3	O
was	O
released	O
on	O
July	O
19	O
,	O
2020	O
.	O
</s>
<s>
As	O
open	B-Application
source	I-Application
software	I-Application
,	O
NHibernate	B-Language
has	O
received	O
many	O
contributions	O
from	O
its	O
users	O
.	O
</s>
<s>
Implementation	O
of	O
LINQ	B-Language
has	O
allowed	O
Language	B-Language
Integrated	I-Language
Query	I-Language
use	O
with	O
NHibernate	B-Language
.	O
</s>
<s>
The	O
NHibernate	B-Language
Profiler	O
is	O
an	O
Object	B-General_Concept
–	I-General_Concept
Relational	I-General_Concept
Mapping	I-General_Concept
tool	O
(	O
ORM	O
)	O
that	O
serves	O
as	O
a	O
real-time	O
visual	O
debugger	O
for	O
NHibernate	B-Language
.	O
</s>
<s>
It	O
identifies	O
inefficient	O
SQL	B-Language
data	O
queries	O
to	O
eliminate	O
unnecessary	O
work	O
by	O
the	O
database	O
to	O
boost	O
overall	O
performance	O
of	O
the	O
application	O
.	O
</s>
<s>
The	O
NHibernate	B-Language
Profiler	O
also	O
alerts	O
users	O
to	O
data	O
queries	O
that	O
cost	O
too	O
much	O
in	O
time	O
and	O
directs	O
them	O
to	O
the	O
exact	O
line	O
in	O
the	O
C#	B-Application
code	O
.	O
</s>
<s>
Here	O
a	O
code	O
snippet	O
to	O
add	O
an	O
object	O
to	O
the	O
database	O
and	O
shows	O
how	O
to	O
retrieve	O
,	O
modify	O
and	O
update	O
an	O
object	O
in	O
the	O
database	O
using	O
NHibernate	B-Language
.	O
</s>
<s>
NHibernate	B-Language
's	O
configuration	O
may	O
affect	O
when	O
NHibernate	B-Language
executes	O
SQL	B-Language
statements	O
.	O
</s>
