VALUES (5, "", "", "", Null);
UPDATE :
UPDATE <-> < >,
< >
<6>:= < >.
, , .
19.
37 47.
:
UPDATE WHERE =37 := + 10
QBE. :
_19
| [] + 10 | |
| =37 |
:
:
Ø ,
Ø ,
\ \ \
Ø
\
, . , NULL.
SQL:
UPDATE SET . = . + 10
WHERE ((.) = 37);
DELETE :
DELETE <->,
< - > , .
20.
51 - 59, .. .
:
DELETE WHERE > 50
QBE. :
_20
| >50 |
:
:
Ø ,
Ø ,
\ \ \
Ø
\
SQL:
DELETE *
FROM
WHERE ((.)>50);
is NULL. , , , SQL:
DELETE *
FROM
