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2.
:
1. . , . .
2. . , , , , , . 4 :
. , .
. , . , .
. , . , .
. , . .
3. : , , . , .. .
,: ; , ; ,
3.
, / . , , :
³ → → → → → , , → .
() , .
1. , . , . : , .
2. , , ( ) .
|
|
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3. .
4. , → , ( (!)).
5. .
6. → .
7. .
:
- ;
- , , ;
-
.
. , ( ) "", . , , .
1. ?
2. ?
3. ?
4. ?
5. ?
6. ?
7. ?
8. ?
9. ?
5
5.1. SQL
:
1. SQL
2.
3.
4. ,
1. SQL
SQL 70- XX , IBM . SQL Structured Query Language ( ), sequel ( ). DB2 IBM. (COBOL, ), ' , SQL . , , , .
, - , 䳿 , . SQL.
(American National Standards Institute - ANSI) ̳ (International Standards Organization ISO) . , , .
SQL :
- , ;
- , ;
- ;
- ;
- .
ANSI-92 ANSI-99, SQL . :
|
|
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(#F, . , , )
(#D, #F. , ². , )
(#, # D, , . )
(#G, #D, , , ʳ, #0)
(#$, )
в(#R, , , ̳)
ֲ (#, #G. #$, #R, , . )
SQL- :
1. Access.
2. : ³ → → → → → .
3. - SQL. SQL.
4. - .
2.
. , SELECT FROM. FROM , , SELECT - () .
SELECT ()
FROM ()
. ֳ ' - .
. SELECT . , , :
SELECT , , ʳ
FROM
. , SELECT *:
SELECT *
FROM
. SQL , - . () , DISTINCT ( ALL). , , , :
SELECT DISTINCT ( )
FROM ֲ
DISTINCT ( ). .
. SELECT . ' ( ' AS). , :
SELECT AS _, AS _
FROM
3.
. WHERE. , . WHERE:
- ;
- ;
- , , SELECT.
:
SELECT
FROM
WHERE = ""
4. ,
SQL , , , .
, TRUE FALSE. ' WHERE. = <>.
, . :
- , +, -,*,/.
- , ||.
- , AND, OR, NOT
- -, UNION, INTERSECT, EXCEPT ( MINUS).
- , >, <, =, <>, >=, <=.
, . 1.
1.
| = | SELECT * FROM WHERE = 1500 | |
| !=, <> | SELECT * FROM WHERE != 1500 | |
| >, < | , | SELECT * FROM WHERE > 1500 SELECT * FROM WHERE < 1500 |
| >=, <= | , | SELECT * FROM WHERE >= 1500 SELECT * FROM WHERE <= 1500 |
| IN | 1. SELECT * FROM WHERE IN ("","") 2. SELECT * FROM WHERE IN (SELECT FROM WHERE ="5261815") | |
| NOT IN | !=ALL. | 1. SELECT * FROM WHERE NOT IN (SELECT FROM WHERE =23456) |
| ANY,SOME | =,!=, >,<,>=<<= , , , , | SELECT * FROM WHERE =ANY (SELECT FROM WHERE = 7) |
| ALL | =,! ~ >, <, <= >=. , , , | SELECT * FROM WHERE >= ALL (1400,3000) |
| EXISTS | TRUE, , , | SELECT FROM WHERE EXISTS (SELECT * FROM WHERE .#F = . #F) |
| IS | NULL | SELECT FROM WHERE IS NULL |
|
|
|
.
. 1. , 20 25 , , .
| ˳ | , 5 | , 30 |
SELECT ,
FROM
WHERE >= 20 AND <= 25
2.
| ˳ | , 10 | , 15 | , 20 |
SELECT
FROM
WHERE = OR =
5.2.
, , . SQL, : INSERT, UPDATE DELETE.
5.1 . INSERT
INSERT . :
- INSERT. INTO..VALUES
- INSERT.. INTO .SELECT
INSERT...VALUES :
INSERT INTO <' > (< 1> [, < 2>]...) VALUES (< 1> [, < 2>]....)
:
- , , ;
- ;
- VALUES INSERT INTO.
37. .
INSERT INTO (#F. . , , )
VALUES (15, "", "", 5, 25000)
', . .
|
|
|
39. .
INSERT INTO
VALUES (173, 13, "", NULL, "526-18-15")
INSERT...SELECT
INSERT...SELECT ( ) , , . , INSRT-.SEL , . :
INSERT INTO <' > (< >)
SELECT < >
FRO <' >
WHERE < >
SELECT INSERT.
40 , _, _, __, , , .
INSERT INTO (^, _, _)
SELECT ., ., .
FRO , ,
WHERE .#F = .#F AND
.#D = .#D
INSERT...SELECT :
- SELECT , ;
- INSERT INTO SELECT;
- INSERT INTO SELECT.
. UPDATE
UPDATE . :
UPDATE < ' >
SET < 1> = < 1>
[. < 2> = < 2>]...
[WHERE < >]
. , WHERE , SET.
41. 250 300.
UPDATE
.SET.. : = 250300
WHERE =""
41. 5 10
UPDATE
.SET.. : Գ = 5, =4
WHERE =10
. WHERE , .
42. 260 500.
UPDATE
SET =26050
41. 5
UPDATE
.SET.. : Գ = 5, =4
WHERE =10
. , , .
43. 1
UPDATE
SET = +1
44. 5 %.
UPDATE
SET = + /20
WHERE #F IN (SELECT #F
FROM
WHERE. . - "")
5.4 . DELETE
DELETE :
DELETE FROM <' > [WHERE ]
WHERE
- ,
- ,
-
- .
DELETE.
.
DELETE, INSERT UPDATE, .
WHERE , FROM , . INSERT UPDATE.
, . DROP TABLE. .
45 , .
DELETE FROM ֲ
WHERE IN (""."")
46 ,
DELETE FROM
47. , .
DELETE FROM
WHERE #S!=ALL (SELECT #S
FROM ֲ)
.
CREATE DATABASE
SQL. :
CREATE DATABASE <' >
|
|
|
CREATE DATABASE 䳿:
- ;
- (, ), ;
- .
5.6 . CREATE TABLE.
:
CREATE TABLE <' >
(< 1> < 1> [ NOT NULL ]
[, < 2> < 2> [ NOT NULL]]...)
ϳ CREATE TABLE ' . NOT NULL NULL- .
43.
CREATE TABLE (#F NUMBER (10),
CHAR(50) NOT NULL,
CHAR(25).
CHAR(5),
NUMBER(6.2))
. CREATE TABLE. :
CREATE TABLE < >(< >)
AS (SELECT < >
FROM < >
[WHERE...])
.
5.7
Byte 1
Integer
Single
NUMBER
Double
Date
Currency
Memo
5.8 . ALTER TABLE.
, . ALTER TABLE : .
:
ALTER TABLE <' >
[ADD <> < >|
ALTER <> <>|
DROP <> <>]
5.9. . DROP TABLE
SQL , . DROP TABLE ' . , . :
DROP TABLE <' >
. DROP DATABASE. DROP DATABASE :
DROP DATABASE <' >
1. SQL?
2. ?
3. SELECT?
4. FROM?
5. SQL-?
6. DISTINCT SELECT?
1. .. . . , 2000. 88 .
2. ., . Microsoft Office 95. - .: Microsoft Access, 2002. - 1000.
3. ., ., . . - .: , 1997. - 704.
4. . ., .. Delphi 5 .: , 2000. 656
5. .: - MS ACCESS 97. - .: , 1998. - 232.
6. .., .. MS ACCESS. - : , 2003. - 46.
7. , , , : , , "", 2001.-1120 .
8.. .. . . . ... -, . . 2002, 666.
