<s>
In	O
the	O
database	O
structured	B-Language
query	I-Language
language	I-Language
(	O
SQL	B-Language
)	O
,	O
the	O
DELETE	B-Language
statement	O
removes	O
one	O
or	O
more	O
records	O
from	O
a	O
table	B-Application
.	O
</s>
<s>
Some	O
database	O
management	O
systems	O
(	O
DBMSs	O
)	O
,	O
like	O
MySQL	B-Application
,	O
allow	O
deletion	O
of	O
rows	O
from	O
multiple	O
tables	O
with	O
one	O
DELETE	B-Language
statement	O
(	O
this	O
is	O
sometimes	O
called	O
multi-table	O
DELETE	B-Language
)	O
.	O
</s>
<s>
Delete	B-Language
rows	O
from	O
table	B-Application
pies	O
where	O
column	B-Application
flavor	O
equals	O
Lemon	O
Meringue	O
:	O
</s>
<s>
Delete	B-Language
rows	O
in	O
trees	O
,	O
if	O
the	O
value	O
of	O
height	O
is	O
smaller	O
than	O
80	O
.	O
</s>
<s>
Delete	B-Language
all	O
rows	O
from	O
mytable	O
:	O
</s>
<s>
Delete	B-Language
rows	O
from	O
mytable	O
using	O
a	O
subquery	O
in	O
the	O
where	O
condition	O
:	O
</s>
<s>
Delete	B-Language
rows	O
from	O
mytable	O
using	O
a	O
list	O
of	O
values	O
:	O
</s>
<s>
More	O
than	O
one	O
person	O
can	O
live	O
at	O
a	O
particular	O
address	O
and	O
a	O
person	O
can	O
live	O
at	O
more	O
than	O
one	O
address	O
(	O
this	O
is	O
an	O
example	O
of	O
a	O
many-to-many	B-Application
relationship	I-Application
)	O
.	O
</s>
<s>
The	O
pa	O
table	B-Application
relates	O
the	O
person	O
and	O
address	O
tables	O
,	O
showing	O
that	O
Joe	O
,	O
Bob	O
and	O
Ann	O
all	O
live	O
at	O
2001	O
Main	O
Street	O
,	O
but	O
Joe	O
also	O
takes	O
up	O
residence	O
on	O
Pico	O
Boulevard	O
.	O
</s>
<s>
In	O
order	O
to	O
remove	O
joe	O
from	O
the	O
database	O
,	O
two	O
deletes	B-Language
must	O
be	O
executed	O
:	O
</s>
<s>
It	O
could	O
be	O
that	O
beyond	O
just	O
having	O
three	O
tables	O
,	O
the	O
database	O
also	O
has	O
been	O
set	O
up	O
with	O
a	O
trigger	O
so	O
that	O
whenever	O
a	O
row	B-Application
is	O
deleted	O
from	O
person	O
any	O
linked	O
rows	O
would	O
be	O
deleted	O
from	O
pa	O
.	O
Then	O
the	O
first	O
statement	O
:	O
</s>
<s>
Transaction	O
log	O
-	O
DELETE	B-Language
needs	O
to	O
read	O
records	O
,	O
check	O
constraints	O
,	O
update	O
block	O
,	O
update	O
indexes	O
,	O
and	O
generate	O
redo	O
/	O
undo	O
.	O
</s>
<s>
Deleting	O
all	O
rows	O
from	O
a	O
table	B-Application
can	O
be	O
very	O
time-consuming	O
.	O
</s>
<s>
Some	O
DBMS	B-General_Concept
offer	O
a	O
TRUNCATE	B-Language
TABLE	I-Language
command	O
that	O
works	O
a	O
lot	O
quicker	O
,	O
as	O
it	O
only	O
alters	O
metadata	O
and	O
typically	O
does	O
not	O
spend	O
time	O
enforcing	O
constraints	O
or	O
firing	O
triggers	O
.	O
</s>
<s>
DELETE	B-Language
only	O
deletes	B-Language
the	O
rows	O
.	O
</s>
<s>
For	O
deleting	O
a	O
table	B-Application
entirely	O
the	O
DROP	O
command	O
can	O
be	O
used	O
.	O
</s>
