<s>
Data	B-Application
query	I-Application
language	I-Application
(	O
DQL	O
)	O
is	O
part	O
of	O
the	O
base	O
grouping	O
of	O
SQL	B-Language
sub-languages	O
.	O
</s>
<s>
These	O
sub-languages	O
are	O
mainly	O
categorized	O
into	O
four	O
categories	O
:	O
a	O
data	B-Application
query	I-Application
language	I-Application
(	O
DQL	O
)	O
,	O
a	O
data	B-Language
definition	I-Language
language	I-Language
(	O
DDL	O
)	O
,	O
a	O
data	B-Application
control	I-Application
language	I-Application
(	O
DCL	O
)	O
,	O
and	O
a	O
data	B-Language
manipulation	I-Language
language	I-Language
(	O
DML	O
)	O
.	O
</s>
<s>
Although	O
often	O
considered	O
part	O
of	O
DML	O
,	O
the	O
SQL	B-Language
SELECT	I-Language
statement	O
is	O
strictly	O
speaking	O
an	O
example	O
of	O
DQL	O
.	O
</s>
<s>
When	O
adding	O
FROM	O
or	O
WHERE	O
data	O
manipulators	O
to	O
the	O
SELECT	B-Language
statement	O
the	O
statement	O
is	O
then	O
considered	O
part	O
of	O
the	O
DML	O
.	O
</s>
