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616
,
,
dBASe, Paradox, FoxPro, Clipper, Rbase
.,
,
,
dBASE-
(X-Base).
dBASe.
,
(
,
Assist
.),
(
),
.
(CREATE, MODIFY, UPDATE, DELETE
.).
(
)
,
(
).
,
.
(
– 1).
:
,
(
,
);
.
,
:
APPEND BLANK, BROWSE, CHANGE, EDIT, INSERT -
,
(
);
DELETE –
(
);
SEEK, FIND, LOCATE –
;
COPY –
;
CONTINUE -
.
:
RECORD n –
n;
ALL –
;
NEXT n –
n
,
;
REST –
,
.
FOR WHILE.
1
(
)
:
,
.
,
:
2
,
: WHILE
]
< 1.1.80
,
FIELDS,
.
19.52.
DELETE
FOR
1 WHILE
2
(
)
,
1.
,
2.
COPY TO
FIELDS
FOR
1 WHILE
yc
2
,
1,
2,
,
.
,
,
617
.
:
,
.
19.53.
JOIN WITH
FOR
FIELDS
,
,
.
,
.
,
.
,
:
(DO WHILE .... END DO);
(IF ... ELSE ... ENDIF);
(DO CASE ... OTHERWISE ...ENDCASE)
.
dBASE-
,
,
,
.
(
)
Q B E
(Query By Example),
,
,
Microsoft Query.
.
.
)
(
).
)
(
)
.
,
:
–
:
*
+
-
/
–
:
> (
)
>= (
)
< (
)
<= (
)
<> (
)
= (
).
–
,
618
:
(AND) –
.
(OR) –
.
(NOT) –
.
:
BETWEEN –
.
IN –
.
IS –
Null
,
(
)
(
).
LIKE –
.
:
;
,
;
,
.
19.55.
1.1.79 –1.1.80
:
1.1.79-
1.1.80
:
QBE
:
QBE
(
)
:
Avg –
;
Count –
;
–
;
Min –
;
Sum –
.
,
.
19.56.
1.1.79 – 1.1.80
:
al
.
.
19.57.
619
:
–
,
today
–
.
,
,
.
19.58.
,
4 5,
(
):
–
.
:
,
,
,
.
,
4 5.
QBE
(
)
,
.
:
ONLY –
–
,
NO –
,
EVERY –
–
,
EXACTLY –
.
SET.
19.59.
,
,
123456
(INSERT),
(DELETE)
(CHANGETO).
SQL
SQL
SQL (Structured Query Language) –
,
(ORACLE, dBASE IY, dBASE Y, Paradox, Access
620
.).
SQL
,
,
. SQL
,
–
,
,
,
,
.
SQL
.
SQL.
SQL
1.
.
:
,
(
).
.
:
-
;
1
,
2 -
;
–
;
–
;
1,
2 -
(
);
–
.
.
(
):
CONSTRAINT
{PRIMARY KEY | UNIQUE |
REFERENCES
[(
)]}
(
):
CONSTRAINT
{PRIMARY KEY (
1[,
2 [,....]]) | UNIQUE
1[,
[, ...]]) | FOREIGN KEY (
1[,
2 [, ...]])
REFERENCES
[(
1 [,
2 [,...]])]}
:
UNIQUE -
(
,
,
);
PRIMARY KEY -
(
;
);
FOREIGN KEY –
(
);
REFERENCES –
.
19.60.
CREATE TABLE
([
] TEXT,
] TEXT,
] DATETIME,
CONSTRAINT
UNIQUE ([
], [
], [
]))
,
: