sql

SQL

QUICK START

VISUAL QUICKSTART GUIDE

SQL

Chris Fehily

, 2003

QUICK START

SQL

004.43 32.973.26-018.1

48 .SQL: . . .: , 2003. 456 .: . ( Quick Start).

ISBN 5-94074-233-5

SQL, - . ANSI SQL-92(SQL2).

SQL , - . - . - , : MS Access, MS SQL Server,Oracle, MySQL PostgreSQL.

, SQL .

48

ISBN 0-201-11803-0 (.)

ISBN 5-94074-233-5 (.)

Authorized translation from the English language edition, entitled SQL: VISUAL QUICKSTARTGUIDE, 1st Edition, 0321118030 by FEHILY, CHRIS, published by Pearson Education, Inc,publishing as Peachpit Press, Copyright 2003.

All rights reserved. No part of this book may be reproduced or transmitted in any form or byany means, electronic or mechanical, including photocopying, recording or by any informationstorage retrieval system, without permission from Pearson Education, Inc. RUSSIAN languageedition published by DMK PRESS, Copyright 2003.

Peachpit Press, 2003

, , 2003

. .

, , . , - , . , .

..................................................................................................................... 11

1. .................................................. 24 SQL ..................................................................... 25Microsoft Access ........................................................................................ 27Microsoft SQL Server ................................................................................ 30Oracle .......................................................................................................... 33MySQL ........................................................................................................ 36PostgreSQL ................................................................................................. 38

2. ......................................................................... 41, ................................................................... 43 .................................................................................... 47 ........................................................................................ 51 .......................................................................................................... 54 ........................................................................................... 57 ..................................................................... 63

3. SQL ........................................................................................... 69 SQL .......................................................................................... 69 ............................................................................................. 75 ......................................................................... 77 .............................................................................. 79 ............................................................. 80 .............................................. 82 ..................................................................... 84 ................................................................... 88 null ............................................................................................. 90

6 SQL

4. ............................... 92 SELECT FROM ............ 93 AS ........ 96 DISTINCT ............................................... 99 ORDER BY ..................101 WHERE .......................109 AND, OR NOT ...114 LIKE ............................................122 BETWEEN .............128 IN .................................................131 null IS NULL ...............134

5. ......................................................................137 .........................................................138 ...................................................................140 ..................................143 || ......................................145 SUBSTRING() .....................................................149 UPPER() LOWER() ..............................153 TRIM() .............................155 CHARACTER_LENGTH() ................................159 POSITION() .............161 ..................................................165 ..................................169 .........................................171 CAST() ..........173 CASE ........179 null COALESCE() ............................................184 NULLIF() ....................185

6. .....................................188 ...................................................189 MIN() ................................192 MAX() .....................194 SUM() ..............................196 AVG() ....198 COUNT() .................................200

7

DISTINCT ....................................................202 GROUP BY .....206 HAVING ......................215

7. .......................................219 .....................................................................220 AS ...........222 .................................................................224 JOIN WHERE ......228 CROSS JOIN......................................233 NATURAL JOIN ...............................236 INNER JOIN ........................................................241 OUTER JOIN .......................................................265 ...................................................................279 UNION ....................286 INTERSECT .....................295 EXCEPT...........................297

8. ..........................................................................................299 ......................................................300 ..........................................................................302 ...................................................................303 .................................................................307 .................................313 null ...................................................................314 ...............................................................316 , , .............................................320 IN ...325 ALL .........................................................333 ANY ........................................................337 EXISTS ..............341 .....................................................347

8 SQL

9. , ...........................348 ........................................349 INSERT ......................................352 UPDATE ...............................358 DELETE ...................................363

10. , ..............................367 ......................................................................368 ..................................369 CREATE TABLE .....371 null NOT NULL ...............373 DEFAULT ......................................................376 PRIMARY KEY ............................................379 FOREIGN KEY .....383 UNIQUE ........................................................389 CHECK ........392 CREATE TEMPORARY TABLE .........................395 SELECT INTO .....................................................398 ALTER TABLE .................401 DROP TABLE ....................404

11. .................................................................................................405 CREATE INDEX .................405 DROP INDEX .....................409

12. ....................................................................................411 CREATE VIEW ........411 .................................................417 .............................................419 DROP VIEW............424

13. ...........................................................................................425 .........................................................................426

....................................................................................................................431

.............................................................................................445

(Becky Morgan) . (Marjorie Baer) , Do you knowSQL?. (Kathy Simpson) , . (Lisa Brazieal) . (Maureen Forys) . (Bryan Steinweg) . (Darren Pennington) , . - (Nancy Aldrich-Ruenzel) .

. . (Iain M. Bank's).

SQL -, , -, -, - , - (). SQL , , - ? , - ( SELECT city, state FROMcustomers). - - , , , -, - , . SQL, - -. , SQL , , - . , SQL , - , Micro-soft Access, Oracle MySQL,

, . -, - SQL. .

SQLSQL : ; ; ; / ; ; -

;

.

-.

SQL , , , - . -

12 SQL

, SQL. , -, , , - . , , , - , - , , , -, . -, - , - , - , - ( - , , -, ), -, , ( , ).

, SQL, , - . , , , - -. - , - . SQL -, , , , - ( - , -). - SQL 3.

: SQL - -. , , - , - -. , - SQL , - . , , -, , SQL - SELECT au_fname, au_lname FROM authorsORDER BY au_lname - , -. -, C Perl, - .

: -, -, ; C Perl, . , , -. SQL ( -). -, , - , , . SQL , , . - SQL

13

, IF-THEN-ELSE, WHILE GOTO1.

- - , - , . , - 1, Microsoft Access Visual Basic, - . , 2, SQL. VB - , - . , , - , Do Until , , . , - SQL. - 20 , . : SQL, , - , - - - , - . , 2 SQL. -, , , -, SELECT, SQL, 100 .

1 - SQL - , . . . .

1. Microsoft Access Visual Basic , ,

Sub GetAuthorNames()

Dim db As Database

Dim rs As Recordset

Dim i As Integer

Dim au_names() As String

Set db = CurrentDb()

Set rs = db.OpenRecordset("authors")

rs.MoveLast

ReDim au_names(rs.RecordCount - 1, 1)

With rs

.MoveFirst

i = 0

Do Until .EOF

au_names(i,0) = ![au_fname]

au_names(i,1) = ![au_lname]

i = i + 1

.MoveNext

Loop

End With

rs.Close

db.Close

End Sub

2. SQL , VB, 1. ,

SELECT au_fname, au_lname

FROM authors;

14 SQL

/ SQL - - , - , , - SQL, , - ,, , -. - - , - C, Java COBOL, - , Perl, PHP Python. PHP, CGI-, SQL, MySQL. - - - PHP - . , - 3, SQL , Access VisualBasic. - SQL - , - , , , SQL., - , - SQL / , SQL--, . SQL, - - . , - .

3. Visual Basic SQL. SQL, SQL

Sub GetAuthorNames2()Dim db As Database

Dim rs As RecordsetSet db = CurrentDb()

Set rs = db.OpenRecordset("SELECT

au_fname, au_lname FROM authors;")

, rs.rs.Closedb.Close

End Sub

. 1. 626- ANSI, X3.135-1992 DatabaseLanguage SQL , , SQL-92. www.ansi.org, , ,

15

SQL . , -. . 1, SQL , - (ANSI). , ANSI -, , - - . , SQL - , - ISO/IEC 9075:1992, 1992 (ISO). - , - ANSI SQL 1992. , - ANSI SQL, SQL-92 SQL, -, - . - , ANSISQL-99. , - SQL-92. , , SQL-92, - , SQL-99. , - ANSI SQL, . - , , -, - , IF, WHILE FOR. , , . -, Oracle Microsoft , PL/SQL Transact-SQL

, SQL. - . , - - SQL, - ANSI (. SQL ).

SQL (DML) - (DDL).

DML , , , , - . - SELECT,INSERT, UPDATE DELETE (. 49).

DDL , - , , -. CREATE, ALTER DROP (. 1013).

SQL ( sequel - ). - , - : S-Q-L. , - , . , - sequel SQL - , , - ,

16 SQL

-, to ( , ). , , - . MySQL ---, PostgreSQL ---.

, SQL. , S-Q-L , - Structured Query Language( ). , SQL SQL, . -? , ANSI. SQL DatabaseLanguage SQL ( SQL). , . - , SQL - , , - SQL, - - :

SQL , - ;

SQL -, - SELECT;

SQL - .

SQL - . 1 3 - , - SQL. - 4 - .

, , , ( Windows, Unix, Mac OS .), , - , , -, , . ( - Windows - DOS).

ANSI SQL, - . , , - - .

www.peachpit.com/vqs/sql ( - ). , : [email protected].

17

, :

-, ;

SQL -;

, - ( - , , Web--, , -, , - );

, - , - - (QBE Query by Example);

- , SQL;

SQL ;

-, / , -, ;

SQL -, Java, C Perl;

Web- - MySQL PostgreSQL;

- SQL.

, :

( , - , 2);

, - ANSI SQL;

( , , , -, , -, , ,, , -, , ).

:

, - ;

, - , - ;

, , ;

- , ;

- .

SQL - : -

-. ( - ) , ;

18 SQL

, SQL

, SQL, -. , - , SQL. , - SQL ( SQL-) . , -, , , , . , - -, , - ODBC JDBC. , . , , SQL. - , , ,, , - SQL-. SQL- Microsoft SQL Server, Oracle,MySQL PostgreSQL (, SQL- , SQL, ). - , SQL, Microsoft Access FileMakerPro. , - SQL server, . , SQL server ( server ) , SQL, , SQLServer ( Server ) SQL Server Microsoft. - () () - , , , -, . -, -, .

19

SQL - ;

3, SQL - . - , :SELECT au_fname, au_lname

FROM authorsORDER BY au_lname;

SQL , -, myname, MyName MYNAME - SQL. , SELECT, NULL CHARACTER (. SQL 3), -, -, , , , -. , -, ,, SQL, . - - ;

. 1 , SQL;

SQL - ('), ("). ( ) . - - , , , ;

, , ,

. () , - .

, - . -, - .

SQL

, ,

- ANSI SQL-92. , -, , -- , - SQL , . , -, (-) ANSI SQL - || ( ), Microsoft + (), MySQL - - CONCAT(), , , a||b || +, CONCAT().

- SQL , - . , , . , MySQL 4.0

20 SQL

( - 4.0).

, - :

Microsoft Access 2002; Microsoft SQL Server 2000; Oracle Release 9i; MySQL 4.0; PostgreSQL 7.1. , . SQL, , - . - ANSI SQL , - .

, DB2, SybaseAdaptive Server, Informix. - , - , SQL ANSI SQL.

Oracle 8i . : , , Oracle 9i, Oracle 8i.

| , , , , -. . ! - A|B|C , , , , , , . - ||. , SQL ()

[] , . -! [A|B|C] -: , ,

{} , . ! - {A|B|C} : , ,

... , - / -

() -, - SQL. - ,

1. ,

21

, . , Oracle , . -, , : (). , - , - , ( ), - -. , -, , - , , .

- , . - - ( - - 2). , , - - .

FileMaker Pro

, FileMaker Pro -, SQL SELECT FROM,WHERE ORDER BY ( . 4). . SQL- FileMaker Pro, SQL Query Builder Execute SQL script. - FileMaker Pro . (Cynthia L. Baron, Daniel Peck)FileMaker Pro 5/5.5 Advanced: VisualQuickPro Guide. , FileMaker Pro - www.filemaker.com.

22 SQL

, , :

; ; .

SQL - , - - . - SQL .sql, , - .txt. - . -, - , , , , - , -, , - - , . - (. . 2), - - (. www.download.com).

2.

Wndows Notepad

Windows edit

Unix, Linux vi, emacs, pico

Mac OS Teach Text, Simple Text

Mac OS X Terminal vi, emacs, pico

SQL, - , - (. - ).

- , - , MicrosoftWord, text only. -, - .

23

, , (. 2). -, SQL-, , , Microsoft Access, books.mdb( ). - , SQL - -.

SQL- - - , SQL. . , SQL- - .

, SQL . -: , . - , - . , , . , SQL, - - . , - -, , . - , -, -, .

11111

25

SQL , - SQL- - : Microsoft Access 2002; Microsoft SQL Server 2000; Oracle 9i; MySQL 4.0; PostgreSQL 7.1. Microsoft Access SQL- , , - SQL- ( - ), - SQL - - Visual Basic. , Microsoft Access, - , . - SQL , - . , ( -), ( - (), ), - .

- ( ), SQL, , 1.1, - .

1.1. listing0101.sql SQL- SELECT, ,


FROM authors

ORDER BY au_lname;

SQL

26

, - .

SQL- , (. - , ).

- , ( - ; - ) , - . , -, . - , , (, , MySQL PostgreSQL) - - .

, path (Windows) echo $PATH ( Unix Mac OS X Terminal) Enter.

, - , . - , Windows ( ), Unix Mac OS X Terminal, - path - , .bash_login, .bashrc, .cshrc, .login, .profile, shrc.

,

- . - , , , -. , , . - Windows (\), , , . Unix/Linux Mac OS X , - (/)., C:\Program Files\MicrosoftSQL Server ( Windows) /usr/local/bin/mysql ( Unix/Linux) - , scripts\lis-ting0101.sql ( Windows) doc/read-me.txt ( Unix) .

27

Microsoft AccessMicrosoft Access , . - Access www.microsoft.com/office/access/. Microsoft Access 2002. , , : Help [ About Mic-rosoft Access ( [ MicrosoftAccess). , Access 2002 - ANSI-89. , , - ANSI-92.

SQL

:1. Options (-

), Tools [Options ( [ ).

2. Tables/Queries (-/).

3. This Database ( ) . . 1.1.

. , ANSI SQL-89 ANSISQL-92 , - . SQL- -, .

- Access ( ANSI SQL query mode).

Microsoft Access

. 1.1. SQL ANSI-92 SQL, ANSI-92 SQL

28

Access , , , , - . , - , Access - SQL. , SQL view. DML DDL ( - ; . SQL -), Access - . DML SELECT, INSERT, UPDATE DELETE, DDL CREATE,ALTER DROP.

SQL

-:

1. - Queries (), Objects(), New (), (.. 1.2).

2. New Query () DesignView (), - OK (. . 1.3).

3. , , -, Close (-).

. 1.3. New Query( ) Design View()

. 1.2. , New ()

. 1.4. DML ( SELECT, INSERT, UPDATE,DELETE), SQL

29

4. -:

DML View [ SQL View ( [ SQL), . . 1.4;

DDL Query [ SQL Specific [ Data De-finition ( [ SQL [), . . 1.5.

5. - - SQL (-, 1.1; . . 1.6).

6. , SQL, Que-ry [ Run ( [ ) .. 1.7.

Access SELECT(. . 1.8), SQL , - , - .

Query - SQL. , Query - Visual Basicfor Applications, - .

. 1.5. DDL( CREATE, ALTER, ROP), DataDefinition

. 1.7. ...

. 1.8. SELECT

. 1.6. - SQL

Microsoft Access

30

Microsoft SQL ServerMicrosoft SQL Server, - Microsoft Access, - - . Microsoft SQLServer Microsoft. Microsoft SQL Server - www.microsoft.com/sql/. - , 120 , www.microsoft.com/sql/evaluation/.

MicrosoftSQL Server 2000. - Microsoft SQL Server, -, SELECT @@VERSION, - Enter, osql - go Enter.

SQL, - SQL Query Analyzer osql. .

SQL Query Analyzer

:

1. Start [ Programs [ Microsoft SQLServer [ Query Analyzer.

2. , OK.

3. - - - , - books (. . 1.9).

. 1.9. (), SQL, Query Analyzer

31

4. SQL - :

SQL , - SQL, - 1.1, - ;

SQL-, File [ Open( [ ), - Open ().

5. Query [ Execute (- [ ). - (. . 1.10).

SQL Query Analyzer, - isqlw.

osql :1. osql -E -d dbname,

: -E SQL Server -

, - ;

dbname , - .

2. SQL, - , 1.1, Enter. , - .

3. go - (. . 1.11).

. 1.10. SELECT Query Analyzer

. 1.11. SQL osql

Microsoft SQL Server

32

osql

osql -E -d dbname -n -i sql_script,

:

-E SQL Server - , - ;

dbname , -;

-n - >;

sql_script , - , - SQL (. - 1.1 . 1.12).

osql

exit quit Enter.

osql

osql -? Enter.

. 1.12. SQL osql

SQL Server - -, . - -E -U login_id, login_id . - .

osql - , - SQL Server, , - -S server. - .

33

OracleOracle , -. - - . -, , - - . www.oracle.com Oracle . - Oracle (otn.oracle.com). , - CD-. Oracle - SQL, - SQL*Plus, sqlplus. , - Oracle 9i. - Oracle 8i. Oracle - SQL*Plus sqlplus. Con-nected to ( ...).

SQL*PLus :1. SQL*Plus. , -

, . , Windows - Programs [ Oracle-OraHome91 [Application Developement [ SQL Plus.

2. , , -. OK (. . 1.13).

. 1.13. SQL*Plus

Oracle

34

Oracle, - , Host String. - SYSTEM, manager.

3. : SQL -

, - SQL Enter; ; (. . 1.14);

- SQL, @sql_script Enter. sql_script -, - SQL; , (. . 1.15).

sqlplus

:

1. :sqlplus user/password@dbname. user , password -, dbname , .

2. SQL (- ).

3. Enter - (. 1.16).

. 1.15. SELECT, SQL*Plus,

. 1.14. SELECT SQL*Plus

35

sqlplus

:sqlplus user/password@dbname @sql_script

user , password , - dbname , - , sql_script , SQL; , -. dbname @sql_script (. . 1.17).

sqlplus

exit quit Enter.

sqlplus

:sqlplus -?

Enter.

, - , - sqlplus /password.

. 1.16. SELECT sqlplus

. 1.17. SELECT sqlplus

Oracle

36

MySQLMySQL ( , - ) . , - . , , - , MySQL SQL(, 4.1 - -). , MySQL - - - , . www.mysql.com. MySQL 4.0. , - , mysql SELECT VERSION(); Enter. SQL, - mysql.

mysql

:1. :

mysql dbname., dbname , - .

2. - SQL, 1.1. - .

. 1.18. SELECT mysql

3. Enter - (. 1.18).

mysql

mysql -tdbname < sql_script,

:

-t ( - , );

dbname , ;

sql_script , SQL (. . 1.19).

37

mysql

exit quit Enter.

mysql

:

1. mysql -? Enter.

2. , , , , - -: mysql -? | more (. . 1), Enter - - (. . 1.20).

. 1.19. SELECT mysql

. 1.20. mysql

MySQL

38

MySQL, mysqld, ansi, MySQL, ANSI SQL.

MySQL - , , , - -, . mysql -h host-u user -p dbname, :

host - -;

user ;

dbname , .

MySQL . , - , - .

PostgreSQLPostgreSQL - . , - , - - ANSI SQL. - , PostgreSQL - - , . www.postgresql.org. PostgreSQL 7.1. , , psql -V Enter. SQL, psql.

39

. 1.21. SELECT psql

psql

:1. psql

dbname. , dbname , .

2. - SQL, , - 1.1. .

3. Enter. - (. . 1.21).

psql

psql -fsql_script db_name., : sql_script -

- , SQL;

dbname , - (. . 1.22).

psql

\q Enter.

. 1.22. psql SELECT

PostgreSQL

40

psql

psql -? Enter (. . 1.23).

Postgre SQL , - -, . psql -h host -Uuser -W dbname, , :

host - -;

user -;

dbname , .

PostgreSQL - . , , - .

. 1.22. psql SELECT

. 1.23. psql

. ., , , , , - . SQL, . -, - SQL,

. 2.1. , . . , : http://www.acm.org/classics/nov95/toc.html. ,

(. . 2.1), - - , . - , - - ,

22222

42

., , , - - , , . , - (. . 2.2). -, , , . -, , -, , - - . -, , - , , - -, - , . , , -, - - . , SQL - , - . , SELECT. , , - , , , , - , - . -, - - . , .

. 2.2. . U , A B . B . , ,

UA B

43

, . - , , -. . 2.1 - . -, , ANSI SQL , - . - SQL, - .

, - , . :

, ;

, -- , , / ,/ - (, -, , , , - - , , , - );

, - (. . 2.3 2.4);

2.1.

SQL

. 2.3. , ,

. 2.4. , , ,. , . , 3 , 4 (34) 12 , , ,

au_id au_fname au_lname

-------- ---------- -----------

A01 Sarah Bucman

A02 Wendy Heydemark

A03 Hallie Hull

A04 Klee Hull

,

44

- , - (. . 2.3 2.4);

-, ( , , );

, , , .

- :

- () , - (, - employees hire_date );

, - , , , - , - ( /- null), - (, - mimetic hire_date, - );

, , (-, ; . );

( - ) - (. . 2.5);

. 2.5. , , , , , ., . , , , . 2.4

au_lname au_id au_fname

------------ ------ ---------

Hull A04 Klee

Buchman A01 Sarah

Hull A03 Hallie

Heydemark A02 Wendy

45

, ( ).

- :

- ( ), (, - -);

- - (-), null;

- (, ) ;

, - ;

- - (. - ).

SELECT (. 48). , -, INSERT, UPDATE DELETE (. 9), , , - CREATE, TABLE ALTERTABLE (. 10).

- , , , , -- (. . 2.6).

. 2.6. , , . , . , , , - , -

,

46

-:

; , -

.

- . - , (, , , , - - ). . - , , -, - : (. . 2.7).

, - , , .

, . , , - , .. -, - .

. , - - . , - phone_number - country_code,area_code subscriber_number.

. 2.7. , . , , Microsoft SQL Server, . , , . , ,

47

, - . , , - , :

; ; -

(, - ).

.

, - (relational), - (rela-tional database), - - (relational set theory), - (torelate) .

-:

- ;

- ;

, , - , . , . ANSI , - -;

( ANSI).

, - , - , - . , - -, , , - , - , . , - . - . - . - (Primary key)., , - , , , . , , . - - :

. - ., - . - , - . , ;

48

. , , , - - ( - );

. , . - , -. , - , , , ;

null. . - , , - , (. - null 3);

. , , - ;

. - , - , ;

. (), () (), - .

- . -. , , , ( ) - .

- - . - -- .

, , - . 2.8. au_fname, - au_lname, , -, , , - . - . , , - , , - , , . , - ( , ), (- ). - : , , , - .. , ( - -), - , -

49

. - au_id, - , - ( , ). . ( ) , - . - , . , - - A02 Christian Kells

, au_id A02. NULL Christian Kells

, au_id, , - null. A05 Christian Kells

, - PRIMARY KEY (. - - PRIMARY KEY - 10).

(, ) -, , , - . - - . , - id, code num, , ( , - ; . ).


-------- --------- -----------

A01 Sarah Buchman

A02 Wendy Heydemark

A03 Hallie Hull

A04 Klee Hull

. 2.8. au_id

50

- -, , , - ISBN , . - , -- , , - -. , - , - -, , , , , .

- , - . , - .

au_id, , au_lname , - .

- - - , - , . ,, , - ( , , --, ). Microsoft Access - AutoNumber, Mic-rosoft SQL Server uniqueiden-tifier IDENTITY, Oracle ROWID, MySQL AUTO_INCREMENT, PostgreSQL - serial.

51

, , , - - . , - ( Foreign key), - . - :

, , , - , ;

-- ;

, , , -, , - , , ;

( ) . - , - ( ) , NULL, . - . , appointments, -, , - ,

patients, , -, , , -, . - . , - , ;

, . - , - ;

, - - NULL ( , , ; . - );

, ;

- - ;

. , - - , - - -. , , - . , emp-loyees, - , employee_id, - - ,

52

boss_id, :

- , - employee_id;

employee_id , - - ( - -, ).

, . 2.9, - , - - ., . - ( ). -, - titles, , publishers - pub_id P05:T05 Exchange of Platitudes P05

, titles, - , - null:T05 Exchange of Platitudes NULL

:T05 Exchange of Platitudes P04

, FOREIGN KEY (. - FOREIGN KEY - 10).

. 2.9. titles pub_id , pub_id, publishers

pub_id pub name

P01 Abatis Publishers

P02 Core Dump Books

P03 Schadenfreude Press

P04 Tenterhooks Press

publishers

title_id title_name pub_id

T01 1977! P01

T02 200 Years of Ger... P03

T03 Ask Your System... P02

T04 But I Did It Unco... P04

titles

53

SQL - - , - , - , (. - FOREIGN KEY - 10).

- null , . , - . null ( null) - - / - - (. null 3)1.

- - (link). - , - . - . , - , - .

1 NULL - , -. , customers - org_id person_id, - organization person -, - - . customers org_id person_id NULL, - . . . .

54

, - . - :

--; --; --.

--

, A B --, A B, B - A. -, --, . -, . - -- - , - : / , - ,/ , - , / , , , - null , ( -) - . , -- , - , - (. . 2.10 2.11).

. 2.10. --. titles royalties, royalties titles. royalties , titles

title_id advance

T01 10000

T02 1000

T03 15000

T04 20000

royalties

title_id title_name

T01 1977!

T02 200 Years of Ger...

T03 Ask Your System...

T04 But I Did It Unco...

titles

. 2.11. , . 2.10. ,

titles

title_idtitle_name

royalties

title_idadvance

55

--

, A B --, A ( , ) - B, B - A. , , , - .

, - -- , - , - , , - (.. 2.12 2.13).

--

, A B --, A ( , ) - B, B - ( , ) A. -- - , (- ), --. - .

. 2.12. --. publishers titles, titles publishers. , publishers, , titles,

pub_id pub name

P01 Abatis Publishers

P02 Core Dump Books

P03 Schadenfreude Press

P04 Tenterhooks Press

publishers

title_id title_name pub_id

T01 1977! P01

T02 200 Years of Ger... P03

T03 Ask Your System... P02

T04 But I Did It Unco... P04

titles

T05 Exchange of Plati... P04

. 2.13. --, . 2.12. publishers, , titles( ), . -

publishers

pub_idpub_name

titles

title_idtitle_namepub_id

56

- - --- -- (. . 2.14 2.15).

. 2.14. --. title_authors -- titles authors --. titles title_authors , authors title_authors. , title_id title_authors , titles. au_id title_authors , authors

title_id au_id

T01 A01

T02 A01

T03 A05

T04 A03

T04 A04

T05 A04

title_id title_name

T01 1977!

T02 200 Years of Ger...

T03 Ask Your System...


T05 Exchange ofPlati...

titles


A01 Sarah Buchman

A02 Wendy Heydemark

A03 Hallie Hull

A04 Klee Hull

authors

title_authors

(join), SQL , - 7.

, - -- , (. ).

- , -.

-- -, --.

. 2.15. --, . 2.14

titles

title_idtitle_name

title_authors

title_idau_id

authors

au_idau_fnameau_lname

57

, , - , - ( ) . - - : , , -, . - . , - - -. - -, ( -- -, , , - , - ).

(Normalization) - - -, - . , - - , . , -, - , - , - :

(1); (2); (3).

- , - . , , 3, 2 (, , 1 ). - -, - () . - :

, , - , - ;

- , , -, - .

, - , , - , , .

(, 4 5), -. , , - 4 5, , , - 3, - 5, , - 4. 4 5,

58

- . , -, - , ( - ), , , -, . - - , . , -, (- , ), - .

, - , :

;

- .

- :

- ( ), , - (. . 2.16);

- - (. . 2.17).

, . 2.16 2.17,

, - . 2.18.

, - -, , , , 1, - 2. , 1 2, :

- ( - );

.

- . , - - , - :

;

- .

: - , - :

-;

( ) - - .

59

title_id title_name authors

-------- --------------------------------- -------------------

T01 1977! A01

T04 But I Did It Unconsciously A03, A04

T11 Perhaps Its aGlandular Problem A03, A04, A06

. 2.16. , authors , ( ). , 1

title_id title_name author1 author2 author3

--------- -------------------------------- -------- -------- --------

T01 1977! A01

T04 But I Did It Unconsciously A03 A04

T11 Perhaps Its aGlandular Problem A03 A04 A06

. 2.17. , . 2.16. , , , ( ; null). . , , 1. :

. 2.18. , , ( ), . title_id, title_id au_id

title_id au_id

T01 A01

T04 A03

T04 A04

T11 A03

T11 A04

T11 A06

title_id title_name

T01 1977!


T11 Perhaps It's a Gla...

60

, 2 . - ( - ) ,, - , - .

, . 2.19, - title_id au_id. au_order, , - , au_phone .

-, - , : - , ? , , - ( ). , , - ( ).

. -, title_authors, . 2.19. - au_order -:

au_order, - title_id? -: , , , , - ;

au_order, au_id? : , - , , , .

, , au_order - . :{title_id, au_id} {au_order} :title_id au_id au_order au_order title_id au_id. , -, . au_phone :

au_phone, title_id? : , - ;

au_phone, au_id? : ! .

, -. au_phone - , , title_authors - 2, , , authors phone_numbers.

, - , - :

;

-.

61

. 2.19. au_phone au_id, title_id. , 2

title_authors

title_idau_idau_orderau_phone

- . , - , , - .

- , , 3, , , . , 3 2.

. - , . 2.20, title_id, - price, - , pub_city, - , , pub_id, - .

3, : - , - ? , , . , , - - , . titles . 2.20. - price - :

pub_id, price? : ;

. 2.20. pub_city pub_id, . titles

titles

title_idpricepub_citypub_id

62

pub_city, price? : .

pub_city - :

price, pub_city? : ;

pub_id, pub_city? : , - -.

pub_id :

price, pub_id? : ;

pub_city, pub_id? : ! , .

: pub_city - - pub_id, , - titles 3, , -, publishers. , - , : A, B? - , : B, A?

-, - : , -, , - , - ? , , . 3 - . , - . , , - , - , , - . , - - . - .

63

SQL - ,, , - , - , , /-/, /-/, //-. , - //. books. - :

, , , . , books , - - , , , , - , , - - . . 2.21 - , - ;

authors

au_idau_fnameau_lnamephoneaddresscitystatezip

title_authors

title_idau_idau_orderroyalty_share

publishers

pub_idpub_namecitystatecountry

titles

title_idtitle_nametypepub_idpagespricesalespubdatecontract

royalties

title_idadvanceroyalty_rate

. 2.21. books

SQL, 9, books, . , , - , - - books, - . , , - , -;

( ) books , - SQL- -. - (, , -) www.dmkpress.ru (. - );

, - null, ;

books . - - .

64

authors

authors , . , - . . 2.22 authors, . 2.22 .

2.2. authors

null (/)

au_id CHAR(3) PK

au_fname VARCHAR(15)

au_lname VARCHAR(15)

phone VARCHAR(12)

address VARCHAR(20)

city VARCHAR(15)

state CHR(2)

zip CHAR(5)

au_id au_fname au_lname phone address city state zip

----- ---------- ---------- ------------ --------------------- ------------- ----- -----

A01 Sarah Buchman 718-496-7223 75 west 205 St Bronx NY 10468

A02 Wendy Heydemark 303-986-7020 2922 Baseline Rd Boulder CO 80303

A03 Hallie Hull 415-549-4278 3800 Waldo Ave, #14F San Francisco CA 94123

A04 Klee Hull 415-549-4278 3800 Waldo Ave, #14F San Francisco CA 94123

A05 Christian Kells 212-771-4680 114 Horatino St New York NY 10014

A06 Kellsey 650-836-7128 390 Serra Mall Palo Alto CA 94305

A07 Paddy OFurniture 941-925-0752 1442 Main St Sarasota FL 34236

. 2.22. authors

65

publishers

publishers . , . . 2.3 publishers, . 2.23 .

2.3. publishers

null (/)

pub_id CHAR(3) PK

pub_name VARCHAR(20)

city VARCHAR(15)

state / CHAR(2)

country VARCHAR(15)

pub_id pub_name city state country

------ -------------------- ------------- ------ ---------

P01 Abatis Publishers New York NY USA

P02 Core Dump Books San Francisco CA USA

P03 Schadenfreude Press Hamburg NULL Germany

P04 Tenterhooks Press Berkeley CA USA

. 2.23. publishers

66

titles

titles . - , - . titles - pub_id, publishers , - .

2.4. titles

null (/)

title_id CHAR(3) PK

title_name VARCHAR(40)

type VARCHAR(10)

pub_id CHAR(3) FK publishers (pub_id)

pages INTEGER

price 1 DECIMAL(5,2)

sales INTEGER

pubdate DATE

contract null, SMALLINT //

. 2.24. titles

title_id title_name type pub_id pages price sales pubdate contract

------- -------------------------------- ---------- ------ ----- ----- ------- ---------- --------

T01 1977! history P01 107 21,99 566 2000-08-01 1

T02 200 Years of German Humor history P03 14 19,95 9566 1998-04-01 1

T03 Ask Your System Administrator computer P02 1226 39,95 25667 2000-09-01 1

T04 But I Did It Unconsciously psychology P01 510 12,99 13001 1999-05-31 1

T05 Exchange of Platitudes psychology P01 201 6,95 201440 2001-01-01 1

T06 How About Never? biography P01 473 19,95 11320 2000-07-31 1

T07 I Blame My Mother biography P03 333 23,95 1500200 1999-10-01 1

T08 Just Wait Until After School children P01 86 10 4095 2001-06-01 1

T09 Kiss My Boo-Boo children P01 22 13,95 5000 2002-05-31 1

T10 Not Without My Faberge Egg biography P01 NULL NULL NULL NULL 0

T11 Perhaps Its a Glandular Problem psychology P01 826 7,99 94123 2000-11-30 1

T12 Spontaneous, Not Annoying biography P01 507 12,99 100001 2000-08-31 1

T13 What Are The Civilian Applications? history P03 802 29,99 10467 1999-05-31 1

titles . 2.4, . 2.24.

67

title_authors

, - authors, , - titles, --, , , - , -. , -, , . title_authors , - titles authors (. ). - title_id au_id - , , titles authors. - au_order, - ( - 1), - royalty_share, - ( 1). . 2.5 title_authors, .2.25 .

2.5. title_authors

null (/)

title_id CHAR(3) PK, FK titles (title_id)

au_id CHAR(3) PK, FK authors (au_id)

au_order SMALLINT

royalty_share DECIMAL(5,2)

title_id au_id au_order royalty_share

-------- ------ -------- --------------

T01 A01 1 1.00

T02 A01 1 1.00

T03 A05 1 1.00

T04 A03 1 0.60

T04 A04 2 0.40

T05 A04 1 1.00

T06 A02 1 1.00

T07 A02 1 0.50

T07 A04 2 0.50

T08 A06 1 1.00

T09 A06 1 1.00

T10 A02 1 1.00

T11 A03 2 0.30

T11 A04 3 0.30

T11 A06 1 0.40

T12 A02 1 1.00

T13 A01 1 1.00

. 2.25. title_authors

68

royalties

royalties , - (, ), , - (, ) . royalties - title_id. royalties -- titles, royalties - , titles.. 2.6 royalties, . 2.26 .

2.6. royalties

null (/)

title_id CHAR(3) PK,FK titles(title_id)

advance () DECIMAL(9,2)

royalty_rate , DECIMAL(5,2)

title_id Advance royalty_rate

--------- ---------- -------------

T01 10000 0,05

T02 1000 0,06

T03 15000 0,07

T04 20000 0,08

T05 100000 0,09

T06 20000 0,08

T07 1000000 0,11

T08 0 0,04

T09 0 0,05

T10 NULL NULL

T11 100000 0,07

T12 50000 0,09

T13 20000 0,06

. 2.26. royalties

SQL

, , , SQL. , - :SQL . , SQL - , - . -, - , SQL, - , -. , SQL , , - , - . , - . - SQL , - . . (E. F. Codd), (Chris Date) (Fabian Pascal), - Internet. -: , , . - ,

33333 SQL, . 2.1, - .

, , SQL. , SQL - SQL, . , -, SQL. -, SQL, - null.

SQL . 3.1 SQL . - . , , SQL. .. , - , . - -. , - , ,

70 SQL

. - .

SQL. SQL , - . SQL -, - - . , , -, ( ).

. SQL - . - SQL SQL, - - - , - . - -, : SELECT, FROM, WHERE, ORDER.

. , -, , SQL -

. 3.1. SQL

SQL

Retrieve authors from New York


FROM authors

WHERE state = 'NY'

ORDER BY au_lname;

SQL -. , - (, -) . . 3.1 SQL, . 3.2 SQL ( - , ).. - , ( ) - , , , , (-) . , 128 . SQL , (- , - ). , , au_fname, au_lname, authors state.

. SQL - 1.

71

3.1. SQL

ABSOLUTE COMMIT ELSE INSERT Null

ACTION CONNECT END INT ONLY

ADD CONNECTION END-EXEC INTEGER OPEN

ALL CONSTRAINT ESCAPE INTERSECT OPTION

ALLOCATE CONSTRAINTS EXCEPT INTERVAL OR

ALTER CONTINUE EXCEPTION INTO ORDER

AND CONVERT EXEC IS OUTER

ANY CORRESPONDING EXECUTE ISOLATION OUTPUT

ARE COUNT EXISTS JOIN OVERLAPS

AS CREATE EXTERNAL KEY PAD

ASC CROSS EXTRACT LANGUAGE PARTIAL

ASSERTION CURRENT FALSE LAST POSITION

AT CURRENT_DATE FETCH LEADING PRECISION

AUTHORIZATION CURRENT_TIME FIRST LEFT PREPARE

AVG CURRENT_TIMESTAMP FLOAT LEVEL PRESERVE

BEGIN CURRENT_USER FOR LIKE PRIMARY

BETWEEN CURSOR FOREIGN LOCAL PRIOR

BIT DATE FOUND LOWER PRIVILEGES

BIT_LENGTH DAY FROM MATCH PROCEDURE

BOTH DEALLOCATE FULL MAX PUBLIC

BY DEC GET MIN READ

CASCADE DECIMAL GLOBAL MINUTE REAL

CASCADED DECLARE GO MODULE REFERENCES

CASE DEFAULT GOT0 MONTH RELATIVE

CAST DEFERRABLE GRANT NAMES RESTRICT

CATALOG DEFERRED GROUP NATIONAL REVOKE

CHAR DELETE HAVING NATURAL RIGHT

CHARACTER DESC HOUR NCHAR ROLLBACK

CHAR_LENGTH DESCRIBE IDENTITY NEXT ROWS

CHARACTER_LENGTH DESCRIPTOR IMMEDIATE NO SCHEMA

CHECK DIAGNOSTICS IN NOT SCROLL

CLOSE DISCONNECT INDICATOR NULL SECOND

COALESCE DISTINCT INITIALLY NULLIF SECTION

COLLATE DOMAIN INNER NUMERIC SELECT

COLLATION DOUBLE INPUT OCTET_LENGTH SESSION

COLUMN DROP INSENSITIVE OF SESSION_USER

SET SUM TRAILING UPPER WHENEVER

SIZE SYSTEM_USER TRANSACTION USAGE WHERE

SMALLINT TABLE TRANSLATE USER WITH

SQL

72 SQL

3.2. SQL

AFTER EQUALS OLD RETURN TEST

ALIAS GENERAL OPERATION RETURNS THERE

ASYNC IF OPERATORS ROLE TRIGGER

BEFORE IGNORE OTHERS ROUTINE TYPE

BOOLEAN LEAVE PARAMETERS ROW UNDER

BREADTH LESS PENDANT SAVEPOINT VARIABLE

COMPLETION LIMIT PREORDER SEARCH VIRTUAL

CALL LOOP PRIVATE SENSITIVE VISIBLE

CYCLE MODIFY PROTECTED SEQUENCE WAIT

DATA NEW RECURSIVE SIGNAL WHILE

DEPTH NONE REF SIMILAR WITHOUT

DICTIONARY OBJECT REFERENCING SQLEXCEPTION

EACH OFF REPLACE SQLWARNING

ELSEIF OID RESIGNAL STRUCTURE

3.1. SQL ()

SOME TEMPORARY TRANSLATION USING WORK

SPACE THEN TRIM VALUE WRITE

SQL TIME TRUE VALUES YEAR

SQLCODE TIMESTAMP UNION VARCHAR ZONE

SQLERROR TIMEZONE_HOUR UNIQUE VARYING

SQLSTATE TIMEZONE_MINUTE UNKNOWN VIEW

SUBSTRING TO UPDATE WHEN

73

SQL . :

, (, - SELECT select );

, , ( );

- ;

- /.

- SQL (.. 3.2), - . , - (. - ). -, - :

- - ;

-;

;

1 - , (, MS SQL Server). . . .

- () -;

-;

(-, - SELECT royalty_share FROM authors; SELECT royalty_share FROM ti-tle_authors;.

SQL -, , .

, - . : group max ( - . . 3.1), groups max_price .

SQL

. 3.2. SQL. , , . 3.1

select au_fname

, AU_LNAME

FROM

uthors WhErE state

= 'NY' order

bY

AU_lname

;

74 SQL

. , -, , : lastname. : , - (last_name) -, - (LastName).

- , - - . , , -, , , .. . 3.3 - . , - - , .

. - , - .

, , , , ( SQL , , ). - .

, Microsoft SQL Server,Oracle, MySQL PostgreSQL - , - /* */. - . , MySQL #.

3.3.

Case () CASE WHEN n 0 THEN x/n ELSE 0 END

Cast ( ) CAST(pubdate AS CHARACTER)

Datatime ( ) start_time + 01:30

Interval ( ) INTERVAL '7' DAY*2

Numeric () (sales*price)/12

String () 'Dear ' || au_fname || ','

75

, 2 , - , . - SQL ., -:

- -, - ;

, - , -, . 3.4;

, , -, . , , integer ( ), - , - , - - , , ( , ). - shaden-freude, - - (-);

3.4.

Character string

Bit string

Exact numeric

Approximate numeric

Datetime

Interval

76 SQL

- - . , 1, 2 10, integer, - : 1, 2,10. , - - '1', '2' '10', - : '1', '10' '2'. : - - , , . , , , . - , - , . , - '10' '2', - 10 , 2;

- . , ( ), , - - ( , , -). 40 12.34 ,'40' 'ennui' , DATE '2002-05-10' TIME '09:45:00' (datetime).

- , CREATE TABLE ALTER TABLE. . 10.

- -. , , - , - .

- . -, SQL , . - , SQL - . , , - , , SQL . -, - , . - , , (Boolean) (monetary). , - , - - .

ORDER BY 4.

77

, , (Character string) - . , , - : -

(-, ) ;

3.5.

CHARACTER . . , , CHARACTER(), , , , 1. . , CHARACTER(),- , , , (, Jack CHARACTER (6) Jack ). , CHARACTER CHAR

CHARACTER VARYING . , . , , CHARACTER VARYING(), , , , 1. . , CHARACTER VARYING(), - , , , CHARACTER, , , (, Jack CHARACTER VARYING(6) Jack). , CHARACTER VARYING, CHAR VARYING CHARVAR

NATIONAL CHARACTER CHARACTER, (Unicode) (. ). SQL NATIONAL CHARACTER , CHARACTER, - N, : Na*b. , NATIONAL CHARACTER, NATIONAL CHAR NCHAR

NATIONAL CHARACTER VARYING CHARACTER VARYING, (Unicode) (. NATIONAL CHARACTER). , NATIONAL CHARACTER VARYING, NATIONAL CHAR VARYING NCHAR VARYING

-, ;

(, - 'A' 'a');

SQL - - ;

, . 3.5.

78 SQL

, . , its, its. - -, , .

- 0 , , - - . , - , - () , , - . VARCHAR .

, - .

- :

Microsoft Access text, memo; Microsoft SQL Server varchar, text,

nchar, nvarchar, ntext;

Oracle char, varchar, varchar2,nchar, nvarchar, nvarchar2;

MySQL char, varchar, nchar,nvarchar, text, tinytext, medium-text, longtext;

PostgreSQL char, varchar, text. , Oracle - null(. null ).

Unicode

(-, , , -, ) . - , - - . , - -. , - ASCII, - 256 = 28 . . , - .

, Unicode - (16- ), - .Unicode 65 536 = 216

. Unicode - . - Unicode -, Internet. - www.unicode.org.

79

(Bit String) , . - :

-, - , 0, ;

0, 1;

(Binary Large Object BLOB), - , - ;

SQL ;

, - . 3.6.

, -.

- , ( - 2) ( 16) -. - - 0 9 A F ( ). - 4 . SQL X ., B'01001011' X'4B'.

3.6.

BIT . - . , , - BIT(), , , - -, 1. - . , - BIT(), - , , , , CHARACTER, , . SQL - , CHARACTER, BIT B., B'01001011' BIT(8)

BIT VARYING . , - -. , , BIT VARYING(), - , , -, 1. - . , - BIT VARYING(), - , , , - , CHARACTER VARYING, , , . , B0101 BIT VARYING(8) B0101

80 SQL

- :

Microsoft Access yes, no, binary,OLE object;

Microsoft SQL Server binary, varbi-nary, image;

Oracle raw, long raw, blob, bfile; MySQL blob, tinyblob, medium-

blob, longblob;

PostgreSQL bit, varbit.

(Exactnumeric) . - - :

, - ;

, - , :

- , - ( );

( );

, - , :

- ( - - );

(-, - 0, , );

, - . 3.7 ( -).

81

3.7.

NUMERIC - , , NUMERIC( [ ,]). - ( 0), - , - . - ( 0), , . , , 0, (Integer)

DECIMAL NUMERIC, - . , - , , -, - DECIMAL( [ ,-]). , , . , DECIMAL DEC

INTEGER . - , INTEGER, , . - INTEGER - . , INTEGER INT

SMALLINT INTEGER, - - . , SMALLINT, -

3.8. 123.89

NUMERIC(5) 124

NUMERIC(5,0) 124

NUMERIC(5,1) 123.9

NUMERIC(5,2) 123.89

NUMERIC(4,0) 124

NUMERIC(4,1) 123.9

NUMERIC(4,2)

NUMERIC(2,0)

. 3.8 , - 123.89 NUMERIC - .

-.

, -. , - -. , - ., '02116' , -, .

, , -, , - - .

82 SQL

-:

Microsoft Access decimal, integer,byte, long integer;

Microsoft SQL Server numeric, de-cimal, integer, smallint, bigint,tinyint;

Oracle numeric, decimal, integer,smallint, number;

MySQL numeric, decimal, integer,smallint, bigint, mediumint, tiny-int;

PostgreSQL numeric, decimal, inte-ger, smallint, bigint.

(Approximate numeric), - , - , - , - . - :

- ;

- - ;

, , , - -, - - ;

-, :

-, 10 - ;

- E E, :

, , - ;

, , ;

, , 2.5E2 == 2.5102 = 250 ( 2.5, 2), 2.5E-2 = 2.5102 = 0.025;

83

, -, :

, - ;

-, , ;

- 3.32193;

- - 0.30103(24 7 , 53 15 );

, - . 3.9.

-.

- :

Microsoft Access single, double; Microsoft SQL Server float, real; Oracle float, real, double

precision, number;

MySQL float, real, double preci-sion;

PostgreSQL real, double precision.

3.9.

FLOAT - - . , FLOAT(precision). -, precision , - , . 1. - - -,

REAL FLOAT, , , - . REAL

-

DOUBLE PRECISION FLOAT, , - . DOUBLE PRECISION REAL ( DOUBLE PRECISION - ). , , -, - -

84 SQL

- (Datetime). , , - :

(UTC; Universal CoordinatedTime), - (Greenwich MeanTime). - SQL-92: SQL UTC, - - (,

3.10.

DATE . - , DATE, - (YEAR, MONTH, DAY), yyyy-mm-dd , 10., 2002-06-14 14 2002 .

TIME . , TIME, - (HOUR, MINUTE, SECOND), hh:mm:ss - , 8 , . , 22:06:57 - 22 , 6 , 57 . , - TIME(), . - , . , 0. - , , , 6. HOUR MINUTE - , SECOND . , - TIME, hh:mm:ss.ssss..., hh 2 HOUR,mm 2 MINUTE, ss.ssss... SECOND ( TIME 8 , ,, - ). TIME :22:06:57.13333. . 3.11

UTC - () 8 -);

- ( , , , );

24- , ( - 13:00, 1:00 PM);

- (-), - (:);

, - . 3.10.

85

3.10. ()

TIMESTAMP DATE - TIME, . : yyyy-mm-dd hh:mm:ss. 19 , , 2002-06-14 22:06:57 - 22 , 6 , 57 ,14 , 2002 . TIMESTAMP, - TIMESTAMP(). , - . , 0. - , , - , 6. yyyy-mm-dd hh:mm:ss.ssss..., TIMESTAMP 20 , , , --

TIME WITH TIME ZONE TIME, - TIME_ZONE_OFFSET, UTC . . , - , INTERVAL HOUR TO MINUTE ( , , - , ) , . 3.11 (. ). , TIME WITH TIME ZONE, - ( ) TIME AT TIME ZONEtime_zone_offset. TIME WITH TIMEZONE: 22:06:57 AT TIME ZONE -08:00. 22 , 06 ,57 , UTC, -8 00 . TIME AT LOCAL. , , . AT -, , AT LOCAL

TIMESTAMP WITH TIME ZONE TIMESTAMP, - TIME_ZONE_OFFSET, UTC . , TIME WITHTIME ZONE, - , : 2002-06-14 22:06:57 AT TIME ZONE 08:00

86 SQL

, , - 5.

-, . , , - 4 ( WHERE) 5 ( ).

SECOND 61.999... , 59.999,, , . - , - ( - - ) , -, , , ( , - ( ) 24 , 365 ). DATETIME . 3.11.

() , , , - , : DATE yyyy-mm-dd, TIME hh:mm:ss, TIMESTAMPyyyy-mm-dd hh:mm:ss.

SQL-92 ( / , B.C.E/B.C), - .

3.11. DATETIME

YEAR 0001 9999

MONTH 01 12

DAY 01 31

HOUR 00 23

MINUTE 00 59

SECOND 00 61.999...(. )

TIME_ZONE_OFFSET -12:59 +13:00

87

(timestamp) - , -, , , , - (, - ).

TIME WITHTIME ZONE , - , - . , UTC , - . , UTC, TIMESTAMP WITH TIME ZONE.

- :

Microsoft Access date/time; Microsoft SQL Server datetime,

smalldatetime;

Oracle date, timestamp; MySQL date, time, datetime, time-

stamp;

PostgreSQL date, time, timestamp. :

--; --; . - 24- 12- (- AM/PM). , .

Microsoft Access - #, , .

Microsoft SQL Server - .

88 SQL

- , , SQL-92 . , - , SQL-92 , -, SQL-92 -, - . - .

- , - - . - - : -

/ , , (-, 09:00 13:00 04:30, 4 30 );

, - - - / (. 5 );

, DATETIME ( YEAR, HOUR,SECOND ..), -, , - , , - + (), - (-), - ;

: Year-month (-) -

;

Day-time ( ) , , ;

, :

- YEAR, MONTH, DAY, HOUR, SECOND, - , INTERVAL HOUR, - 4 25 ;

- start_field TOend_field, -, , ,INTERVAL DAY TO MINUTE, - : 2 ,5 , 10 , :

start_field - YEAR, MONTH, DAY, HOUR, MINUTE;

end_field YEAR, MONTH, DAY, HOUR, MINUTE, SECOND, end_field - - start_field;

, ( - ) (, INTERVAL HOUR(2)),:

89

, 2;

SECOND, , - - , - ( 6), - INTERVAL SECOND (5,2);

- start_-field, end_field ( end_field SECOND, end_field -), INTERVAL DAY(3) TOMINUTE INTERVAL MINUTE(2) TO SE-COND(4);

, - . 3.12.

, - INTERVAL, , , :INTERVAL '15-3' , 15 3 , INTERVAL '-22:06:5.5' 22 , 6 5,5 .

- :

Microsoft Access ; Microsoft SQL Server ; Oracle Interval; MySQL ; PostgreSQL Interval.

3.12.

Year-month - , -, . - :INTERVAL YEAR,INTERVAL YEAR(),INTERVAL MONTH,INTERVAL MONTH(),INTERVAL YEAR TO MONTH,INTERVAL YEAR() TO MONTH

Day-time , , , . :INTERVAL MINUTE, INTERVALDAY(),INTERVAL DAY TO HOUR,INTERVAL DAY() TO SECOND,INTERVAL MINUTE() TO SECOND( )

90 SQL

null - , - null. :

SQL NULL null;

null , , - ;

null , ('') ( - Oracle ; . - DBMS )., - - price NULL, - , , , ;

null - , - , - , NOT NULL (. - null NOTNULL 10);

null - - IS NULL (. null c IS NULL 4);

null . - , - - null . -, -

- (. - AND, OR NOT 4);

null null, - DISTINCT null - (. - DISTINCT 4);

, NULL, - , -, , , null (. - ORDER BY 4);

null - . , - , , null, NULL, :(12*NULL)/4 = NULL (. 5);

, SUM(), AVG() MAX(), NULL (. 6);

, - GROUPBY, null, - - (. GROUPBY 6);

null (. - 7);

null - (. - NULL 8).

91

- , - null. , - - null, - - . , null . - , null, . : null, - -.

null null COALESCE() NULLIF() 5.

, - NULL, .

null . , null , , .

NULL . - 'NULL', null.

null , ( ). -, , . 3.3. au_id authors -, SELECT NULL au_id.

null, - - -, . - NULL, (NULL), . - null.

Oracle ('') null. - -. Oracle null. , null . . au_fname authors NOT NULL ( ). Oracle Kellsey ( A06) (' '), - (''). - 2.

SELECT MAX(au_id)

FROM authors

WHERE au_lname = XXX

MAX(au_id)

----------

NULL

. 3.3. null ,

null

44444 SELECT, SQL, 90% -, -, , , ., SELECT , - . - :SELECT columns

FROM tables

[JOIN joins]

[WHERE search_condition]

[GROUP BY grouping_columns]

[HAVING search_condition]

[ORDER BY sort_columns]

- , :

SELECT, FROM, ORDER BY WHERE ;

GROUP BY HAVING 6; JOIN 7.

,, - , -

(. - ).

- SELECT, -, - SQL -.

: SELECT , . , , , ( - 9).

93

SELECT FROM - SELECT. - -, . - SELECT - , , FROM , .

(. 4.1 . 4.1):

SELECT column

FROM table;

, :

column - - ;

table , column.

(. 4.2 . 4.2):SELECT columns

FROM table;

, :

columns , -;

SELECT FROM

4.1. , , . . . 4.1

SELECT city

FROM authors;

city

-------------------

Bronx

Boulder

San Francisco

San Francisco

New York

Palo Alto

Sarasota

. 4.1. , 4.1

au_fname au_lname city state

---------- ------------ ------------- -----

Sarah Buchman Bronx NY

Wendy Heydemark Boulder CO

Hallie Hull San Francisco CA

Klee Hull San Francisco CA

Christian Kells New York NY

Kellsey Palo Alto CA

Paddy OFurniture Sarasota FL

. 4.2. , 4.2

4.2. , , , . . . 4.2

SELECT au_fname, au_lname, city, state

FROM authors;

94

table - , columns.

- - , - columns, , table.

(. 4.3 . 4.3):SELECT *

FROM table;

, table - - -.

-, -.

au_id au_fname au_lname phone address city state zip

------ --------- ----------- ------------- --------------------- -------------- ----- --------

A01 Sarah Buchman 718-496-7223 75 West 205 St Bronx NY 10468

A02 Wendy Heydemark 303-986-7020 2922 Baseline Rd Boulder CO 80303

A03 Hallie Hull 415-549-4278 3800 Waldo Ave, #14F San Francisco CA 94123

A04 Klee Hull 415-549-4278 3800 Waldo Ave, #14F San Francisco CA 94123

A05 Christian Kells 212-771-4680 114 Horatio St New York NY 10014

A06 Kellsey 650-836-7128 390 Serra Mall Palo Alto CA 94305

A07 Paddy OFurniture 941-925-0752 1442 Main St Sarasota FL 34236

. 4.3. , 4.3

4.3. authors. . . 4.3

SELECT *

FROM authors;

, SELECT FROM.

( -, 2) -, SELECT .

, . 4.1, , , -. - , - DISTINCT .

95

, - , , - . , , - ORDER BY .

null - - NULL(. null 3, - 4.4 . 4.4).

, , - 7.

- . -, , - . , - - , , .

SELECT * - SQL , - . , - SELECT * SQL, , -.

, - ( ) - , .

4.4. ,

SELECT city, state, country

FROM publishers;

city state country

------------- ------ ---------

New York NY USA

San Francisco CA USA

Hamburg NULL Germany

Berkeley CA USA

. 4.4. , 4.4. , state ( , ). state NULL, null, - ,

SELECT FROM

96

AS - . - , . - , -. - , - AS.

- (, -, ), - , , . - -, -, , - , - ..

- SELECT SELECT. SELECT AS , , -. , - :

, -, ;

, , ;

AS , - :

SELECT au_fname AS "First name"; SELECT au_fname "First name".

, - - - , AS, .

:SELECT column1 AS alias1,

column2 AS alias2,

column3 AS alias3,

columnN AS aliasN

FROM table;

, : column1, column2, column3, , columnN -

(,) ;

alias1, alias2, alias3, , aliasN -;

table -, - column1, column2, column3, ,columnN.

97

4.5 - AS, . 4.5 -, . - AS - , -. ,, . - ( ; . ). -, 4.5, :SELECT au_fname AS "First name",

au_lname AS "Last name",

city AS "City",

state,

zip AS "Postal code"

FROM authors;

AS , - ( , ; . - 5).

4.5. AS . AS. -

SELECT au_fname AS "First name",


city AS City,

state,

zip AS "Postal code"

FROM authors;

First name Last name City state Postal code

----------- ------------ -------------- ----- ------------

Sarah Buchman Bronx NY 10468

Wendy Heydemark Boulder CO 80303

Hallie Hull San Francisco CA 94123

Klee Hull San Francisco CA 94123

Christian Kells New York NY 10014

Kellsey Palo Alto CA 94305

Paddy OFurniture Sarasota FL 34236

. 4.5. , 4.5

AS

98

AS ( . - AS 7).

- .

- , . , SELECT SUM(sales) AS "Sum" FROMtitles; SUM. - - SQL 3.

Microsoft Access PostgreSQL AS - ., Oracle PostgreSQL, , ( - ).

- , Oracle - .

, Oracle , - -, , . , CHAR(5) Postal code, Posta.

, - , - . - SELECT AS.

99

DISTINCT -, . , -. , - (. 4.6), - , , - , , . 4.6. , -. - DISTINCT, .

:

SELECT DISTINCT columns

FROM table;

, : columns

, ;

table , .

- 4.7 . 4.7.

, SELECT DISTINCT , - - - , -, - ,

DISTINCT

4.7. , , . . 4.7

SELECT DISTINCT state

FROM authors;

4.6. , , . . 4.6

SELECT state

FROM authors;

state

---

NY

CO

CA

CA

NY

CA

FL

. 4.6. , 4.6. CA NY

state

---

NY

CO

CA

FL

. 4.7. , 4.7. CA, NY

100

. , - 4.8 . 4.8, , - 4.9 . 4.9. , - , , . , .

null ( - ), DISTINCT, , -. SELECT DISTINCT null, - , null - (. null 3).

SELECT ALL. - . , , ( ): , -. SELECT columns FROMtable; SELECT ALLcolumns FROM table;, - : SELECT [ALL | DISTINCT]columns FROM table;.

DISTINCT (- , - ; DISTINCT - DISTINCT 6).

, , , . SELECT DISTINCT * FROM table; SELECT * FROM table; ( table) .

4.8. , , . . 4.8

SELECT city, state

FROM authors;

city state

------------- ------

Bronx NY

Boulder CO

San Francisco CA

San Francisco CA

New York NY

Palo Alto CA

Sarasota FL

. 4.8. , 4.8, - ()

. 4.9. , 4.9. , -, - .

city state

------------- -----

Bronx NY

Boulder CO

San Francisco CA

New York NY

Palo Alto CA

Sarasota FL

4.9. (, ), , ,

SELECT DISTINCT city, state

FROM authors;

101

ORDER BY , - , - . - ORDER BY - ( ) - ( ) . - . , - ORDER BY - SELECT.

:SELECT columns

FROM table

ORDER BY sort_column [ASC | DESC];

, :

columns - , , , ;

sort_column , - ;

table -, columns, sort_column, , , columns;

- ASC,

ORDER BY

, . -, . - ( a < b a b), - , -. , - , , . , - - ('A' < 'a'?), ('A' < ''?), ( Unicode) , , .. , SQL -, . - . - - , - . , MicrosoftSQL Server - exec sp_helpsort. - - - .

` `

102

DESC, , ASC (. - 4.10, 4.11 . 4.10, 4.11).

:SELECT columns

FROM table

ORDER BY sort_column1 [ASC | DESC],

sort_column2 [ASC | DESC],

sort_column3 [ASC | DESC],

sort_columnN [ASC | DESC];

, :

columns - , , , ;

sort_column1, sort_column2,sort_column3, , sort_columnN - , - ;

table , columns, sort_column1,sort_column2, sort_column3, , sort_-columnN, , , columns;

sort_column1,sort_column2, sort_column3, , sort_-columnN - ASC - DESC

4.10. , , , , ( , ASC ). . . 4.10


FROM authors

ORDER BY au_lname ASC;


---------- ----------- ------------- -----








. 4.10. , 4.10.

103

4.11. , , , , ( ). DESC . . . 4.11


FROM authors

ORDER BY au_fname DESC;


-------- ----------- ------------- -----








. 4.11. , 4.11. . , (Kellsey) (). ( null). , , ( )

, - ASC(. 4.12 . 4.12);

sort_column1; , - sort_column1, sort_column2;

, , - sort_column(N-1), sort_columnN.

/, /- , -/ -, columns,SQL - ORDER BY / / , columns.

:SELECT columns

FROM table

ORDER BY sort_num1 [ASC | DESC],

sort_num2 [ASC | DESC],

sort_num3 [ASC | DESC],

sort_numN [ASC | DESC];

, :

columns - , , , ;

ORDER BY

104

sort_num1, sort_num2, sort_num3,, sort_numN - , - 1 , columns, - columns, sort_num1,sort_num2, sort_num3, , sort_numN;

table -, columns, sort_num1, sort_num2,sort_num3, , sort_numN, , , columns;

sort_num1,sort_num2, sort_num3, , sort_numN - - ASC, - DESC, , ASC (. 4.13 . 4.13);

- sort_num1;

, - - sort_num1, sort_num2;

, , - sort_num(N-1), sort_numN.

4.12. , , , , ( , , , ). . . 4.12


FROM authors

ORDER BY state ASC,

city DESC;


-------- ----------- -------------- -----








. 4.12. , 4.12

105

SQL , - null ( ) , - null, ( -) , - null. - SQL -, null , (. DBMS -, null 3, - 4.14 . 4.14).

-, , SELECT (. 4.15 . 4.15). -, , - , - , SELECT(. 4.13 . 4.13).

ORDER BY - (. 4.16, . 4.16 - AS ).

, ORDER BY .

4.13. , , , , , () ( 4 SELECT), ( ) ( 2 SELECT). . . 4.13


FROM authors

ORDER BY 4 ASC, 2 DESC;


--------- ------------ ------------- -----








. 4.13. , 4.13

ORDER BY

106

, - OR-DER BY, , , - , - - . (. . 4.10, 4.12, 4.13), - ORDER BY, . , - .

ANSI - ORDER BY - CURSOR , - SELECT. , - , , . -, - SQL - ORDER BY SELECT ( , ).

- . 5 , , (. - 4.17 . 4.17).

ORDER BY - -, - , .

4.14. null, , , , . . . 4.14

SELECT pub_id, state, country

FROM publishers

ORDER BY state ASC;

pub_id state country

------ ----- --------

P03 NULL Germany

P02 CA USA

P04 CA USA

P01 NY USA

. 4.14. , 4.14. , ( ) ., , null ( ). , null ( ),

107

4.15. , (zip) , . . . 4.15

SELECT city, state

FROM authors

ORDER BY zip ASC;

city state

------------- -----

New York NY

Bronx NY

Sarasota FL

Boulder CO

San Francisco CA

San Francisco CA

Palo Alto CA

. 4.15. , 4.15. : ( ), , . , , ,

ORDER BY

4.16. ORDERBY , . . . 4.16

SELECT au_fname AS "First name",


state

FROM authors

ORDER BY state ASC,

"Last name" ASC,

"First name" ASC;

First name Last name state

----------- ----------- -----

Hallie Hull CA

Klee Hull CA

Kellsey CA

Wendy Heydemark CO

Paddy OFurniture FL

Sarah Buchman NY

Christian Kells NY

. 4.16. , 4.16

, , - - , , . , , , - .

, - , UNION ( - UNION 7).

108

4.17. . . . 4.17

SELECT title_id,

price,

sales,

price * sales AS "Revenue"

FROM titles

ORDER BY "Revenue" DESC;

title_id price sales Revenue

-------- ------ ------- ------------

T07 23.95 1500200 35929790.00

T05 6.95 201440 1400008.00

T12 12.99 100001 1299012.99

T03 39.95 25667 1025396.65

T11 7.99 94123 752042.77

T13 29.99 10467 313905.33

T06 19.95 11320 225834.00

T02 19.95 9566 190841.70

T04 12.99 13001 168882.99

T09 13.95 5000 69750.00

T08 10.00 4095 40950.00

T01 21.99 566 12446.34

T10 NULL NULL NULL

. 4.17. , 4.17. , (, )

Microsoft Access, Mic-rosoft SQL Server PostgreSQL - null - , Oracle MySQL .

- ORDERBY. , Microsoft SQL Server - ntext, text image, Oracle blob, clob, nclob bfile. - SELECT ORDER BY.

Microsoft Access ORDER BY. , Access , - 4.17, - ORDER BY - : ORDR BY price * sales DESC, , - , - : ORDER BY 4DESC.

109

WHERE - , - -. , - WHERE - . - , - - SELECT . WHERE - - -, - , - , - . , -, , , , : -, (-,, true, false unknown). , - - null ( ). WHERE - , , , -, . (. . 4.1), SQL - -, - - , , -

4.1.

SQL

=, , =

LIKE

BETWEEN

IN

null IS NULL

WHERE

110

( - 5). - (. . 4.1), . - AND, OR NOT - - (. ).

(. . 4.2) - : , . , -, , :

-, > - , < - (. 3 - ORDER BY - );

, > , < ;

, > - , < ( , year, month, day ..).

, - -. - , :

;

;

4.2.

=

<

>=

111

, - , - , -, .

:SELECT columns

FROM table

WHERE test_column op value;

, :

columns - , , , ;

table , columns;

, :

test_column - - table, - columns;

op - , - . 4.2;

value -, test_column(. . 4.18 4.20).

SELECT - ORDER BY, - WHERE, WHERE ORDER BY.

4.18. , , (Hull). . . 4.18

SELECT au_id, au_fname, au_lname

FROM authors

WHERE au_lname 'Hull';

4.19. , , . . . 4.19

SELECT title_name, contract

FROM titles

WHERE contract = 0;


---- ------- ---------

A01 Sarah Buchman

A02 Wendy Heydemark

A05 Christian Kells

A06 Kellsey

A07 Paddy OFurniture

. 4.18. , 4.18

title_name contract

--------------------------- ----------

Not Without My Faberge Egg 0

. 4.19. , 4.19

WHERE

112

null -, null. , - null, . - , null, null ISNULL . - null null 3.

, ( WHERE, - WHERE) , . : expr1 op expr2, expr1 expr2 . - , , -, , , , , ( , ; . 4.21 . 4.21). - - 5.

WHERE , SUM() COUNT(). - 6.

, - -, .

4.20. , 2001 . . . 4.20

SELECT title_name, pubdate

FROM titles

WHERE pubdate >= DATE '2001-01-01';

4.21. , . , . . . 4.21

SELECT title_name,

price * sales AS 'Revenue'

FROM titles

WHERE price * sales > 1000000;

title_name pubdate

---------------------------- ----------

Exchange of Platitudes 2001-01-01

Just Wait Until After School 2001-06-01

Kiss My Boo-Boo 2002-05-31

. 4.20. , 4.20

title_name Revenue

------------------------------ ------------

Ask Your System Administrator 1025396.65

Exchange of Platitudes 1400008.00

I Blame My Mother 35929790.00

Spontaneous, Not Annoying 1299012.99

. 4.21. , 4.21

113

SQL , - , , ('A' = 'a') ('A' 'a'). , MicrosoftAccess, Microsoft SQL Server MySQL - , Oracle PostgreSQL -, - .

Microsoft Access, - , - DATE, , #. -, -, 4.20, - WHERE - #2001-01-01#.

Microsoft SQL Server, - , DATE. , - , - 4.20, - WHERE '2001-01-01'.

PostgreSQL - , - NUMERIC DECIMAL, ( - ), - NUMERIC DECIMAL( - ). - CAST() - 5.

WHERE

114

AND, OR NOT , - WHERE . -, -, , -, - . AND OR, . AND OR - NOT , , . - - , : , . - ( , ), - , - 2VL. , - : , . 2VL , , . , -. null. - , (. - null 3)., 2VL -, SQL

(3VL). - , - - , , : , , . ,, , -. - . null . - , , null - IS NULL .

AND

AND:

true () , true;

. 4.3, -, - - AND, :

;

- ;

AND ;

- AND , , , - true;

115

( WHEREcondition1 AND condition2 WHERE condition2 AND con-dition1);

- , , AND -, : -, , ( - ).

AND 4.224.23 . 4.224.23.

OR

- OR:

true () , - true;

OR - . 4.4;

- OR , - true , true;

( , AND);

4.22. -, 20 . . . 4.22

SELECT title_name, type, price

FROM titles

WHERE type = 'biography' AND price = 'H'

ANDau_lname

117

4.25. ,, , , . , , , null WHERE, OR. . . 4.25

SELECT pub_id, pub_name, state, country

FROM publishers

WHERE (state = 'CA')

OR (state 'CA');

4.24. , -, , -. . . 4.24


FROM authors

WHERE (state = 'NY')

OR (state = 'CO')

OR (city = 'San Francisco');


--------- --------- -------------- ------






. 4.24. , 4.24

pub_id pub_name state country

------ ----------------- ------ --------

P01 Abatis Publishers NY USA

P02 Core Dump Books CA USA

P04 Tenterhooks Press CA USA

. 4.25. , 4.25

NOT -, - , - (, WHERE NOT state = 'CA' , - WHERE state NOT = 'CA' , );

,, - , NOT. , ,

- 20 , :

SELECT title_id, type, price

FROM titles

WHERE NOT type = 'biography'

AND NOT price < 20;

- . -:SELECT title_name, type, price

FROM titles

WHERE NOT type = 'biography'

AND price < 20;

AND, OR NOT

118

, , -. -;

NOT -. , WHERE NOTstate = 'CA' WHERE state 'CA' -;

.

NOT 4.264.27 . 4.264.27.

AND, OR NOT

SQL AND, OR, NOT - . - - SQL. - - 5. , - , - , NOT, AND, OR. - , - , . , - , , ,

4.26. , . . . 4.26

SELECT au_fname, au_lname, state

FROM authors

WHERE NOT (state = 'CA');

4.27. , 20 15 000 . . . 4.27

SELECT title_name, sales, price

FROM titles

WHERE NOT (price < 20)

AND (sales > 15000);

au_fname au_lname state

---------- ----------- -----

Sarah Buchman NY

Wendy Heydemark CO

Christian Kells NY

Paddy OFurniture FL

4.26. , 4.26

title_name sales price

----------------------------- ------ ------

Ask Your System Administrator 25667 39.95

I Blame My Mother 1500200 23.95

. 4.27. , 4.27

119

., -, , x AND NOTy OR z (xAND (NOT y)) OR z. , , - , , - . , , -, , 20 , , 4.28, . , ( ) AND , OR, 4.28 - :

1. --, 20 .

2. ( ).

3. title_id,type, price ( , , ; . . 4.28).

, OR AND. - 4.28 . -, 4.29, :

1. - ( ).

4.28. , , 20 , . , AND OR. . .4.28


FROM titles

WHERE type = 'history'

OR type = 'biography'

AND price < 20;

title_id type price

-------- --------- -----

T01 history 21.99

T02 history 19.95

T06 biography 19.95

T12 biography 12.99

T13 history 29.99

. 4.28. , 4.28. , , 20 . ,

AND, OR NOT

120

2. , , , 20 -.

3. - title_id, type, price (- , ,; . . 4.29).

AND, OR NOT - , - - .

- , - WHERE OR - , OR , . : WHEREstate = 'NY' OR 'CA'. -: WHERE state = 'NY' OR state = 'CA'.

SQL SQL. , - 10 - 30 . , SQL, :

SELECT title_name, price

FROM titles

WHERE price30;

, ( ) , - , (

4.29. , 4.28, , OR , AND. . . 4.29


FROM titles

WHERE (type = 'history'

OR (type = 'biography')

AND price < 20;

title_id type price

-------- ----------- ------

T02 history 19.95

T06 biography 19.95

T12 biography 12.99

. 4.29. , 4.29.

121

) 10 -, 30 . AND - . , - , , SQL AND( - , ), OR, , -, , - ( 1 2): WHEREprice30. WHERE -, .

- - (. . 4.6). - , .

-. - . 4.6 -, - NOT , , NOT , . -:

NOT ((p AND q) OR (NOT p AND r)) =

= NOT (p AND q) AND NOT (NOT p AND r) =

= (NOT p OR NOT q) AND (p OR NOT r)

MySQL, , False AND Unknown - Unknown, False, , , . 4.3.

4.6.

-

NOT (p AND q) (NOT p) OR (NOT q)

NOT (p OR q) (NOT p) AND (NOT q)

NOT (NOT p) P

AND, OR NOT

122

LIKE - , - -- . , - , - . - LIKE, - (- : ) , - - ( : , , -?). LIKE:

, ;

- , - . - - , - , - -, - . - - , , -. - - , -. . 4.7 - -,

4.7.

-

% ,

_

123

. 4.8 ;

- (. DBMS WHERE );

- LIKE, - LIKE NOT ( - NOT LIKE LIKE);

LIKE AND OR;

4.8.

'A%' , ( ) A, A. , -: Anonymous, AC/DC

'%s' , - s, s. , , s , . : 'DMBSes','Victoria Falls'

'%in%' , in. 'in', 'inch', 'Pine', 'linchpin', 'lynchpin'

'____' , 4. '', ' ' 'Jack'

'Qua__' 5 , Qua. - 'Quack', 'Quaff' 'Quake'

'_re_' , 4 ; re. - : 'Tree', 'area' 'fret'

'_re%' 3 ; re. : 'Tree', 'area', 'fret', 'fretful' 'freeze'

'%re_' 3 ; , , e r -. : 'Tree','area', 'fret', 'red' 'Blood red'

, LIKE (=) . . 4.2, NOT LIKE (). , WHEREcity LIKE 'New York' - WHERE city = 'New York'.

:SELECT columns

FROM table

WHERE test_column [NOT] LIKE

'pattern';

LIKE

124

, :

columns , - , -- ;

table , - columns;

, , - :

test_column - - table, - columns;

pattern , - - test_column;

- , . 4.8;

, - , - LIKE, NOT LIKE(. . 4.304.33).

SQL , ( -, ), . - - - , - , . ,

4.30. , Kel. . . 4.30


FROM authors

WHERE au_lname LIKE "Kel%";

au_fname au_lname

--------- ---------

Christian

sql

Documents

ms sql server

microsoft sql server

ansi sql92sql2

peachpit press

pearson education

ms access

dmk press

mysql postgresql