, WHERE SELECT -, SELECT. : TRUE, FALSE UNKNOUN. - , TRUE.
( ):
::=
[ (] [ NOT ]
{
| between
| in
| like
| null
|
| exist
| unique
| match
| overlaps }
[{ AND | OR } ] [) ]
[ IS [ NOT ] { TRUE | FALSE | UNKNOWN }]
::=
{= | < | > | <= | >= | <>}
33. :
POSTAV.VOLUME > 10034. :
(PD.PNUM, PD.DNUM) = (1, 25)PD.PNUM = 1 AND PD.DNUM = 25
between::=
[ NOT ] BETWEEN
AND
35. PD.VOLUME BETWEEN 10 AND 100
in::=
[ NOT ] IN
{(Select-) | ( .,..)}
36.
P.PNUM IN (SELECT PD.PNUM FROM PD WHERE PD.DNUM=2)37.
P.PNUM IN (1, 2, 3, 5) like::=
- [ NOT ] LIKE
- [ ESCAPE ]
. LIKE - -. - :
- "_" -,
- "%" - ( 0 ).
null::=
IS [ NOT ] NULL
. NULL , null-.
::=
{= | < | > | <= | >= | <>}
{ ANY | SOME | ALL } (Select-)
. ANY SOME .
. ANY SOME, TRUE, , (select-).
. ALL, TRUE, , (select-).
38.
P.PNUM = SOME (SELECT PD.PNUM FROM PD WHERE PD.DNUM=2) exist::=
EXIST (Select-)
|
|
. EXIST TRUE, (select-) .
unique::=
UNIQUE (Select-)
. UNIQUE TRUE, (select-) .
match::=
MATCH [ UNIQUE ]
[ PARTIAL | FULL ] (Select-)
. MATCH , , , .
overlaps::=
OVERLAPS
. OVERLAPS, , , .