, , . , , . , , , , Mary Smiths; , , . . ( ), , , . . ; , . , , . , , , . , 19.
, ( ) . , "" " 3". , , , . , . , , cname , odate . . .
1.1, 1.2, 1.3 , , , , SQL. , E. SQL , , , .
, , . , , , . . . , , , .
1.1:
SNUM | SNAME | CITY | COMM |
1001 | Peel | London | .12 |
1002 | Serres | San Jose | .13 |
1004 | Motika | London | .11 |
1007 | Rifkin | Barcelona | .15 |
1003 | Axelrod | New York | .10 |
1.2:
|
|
CNUM | CNAME | CITY | RATING | SNUM |
2001 | Hoffman | London | 100 | 1001 |
2002 | Giovanni | Rome | 200 | 1003 |
2003 | Liu | SanJose | 200 | 1002 |
2004 | Grass | Berlin | 300 | 1002 |
2006 | Clemens | London | 100 | 1001 |
2008 | Cisneros | SanJose | 300 | 1007 |
2007 | Pereira | Rome | 100 | 1004 |
1.3:
ONUM | AMT | ODATE | CNUM | SNUM |
3001 | 18.69 | 10/03/1990 | 2008 | 1007 |
3003 | 767.19 | 10/03/1990 | 2001 | 1001 |
3002 | 1900.10 | 10/03/1990 | 2007 | 1004 |
3005 | 5160.45 | 10/03/1990 | 2003 | 1002 |
3006 | 1098.16 | 10/03/1990 | 2008 | 1007 |
3009 | 1713.23 | 10/04/1990 | 2002 | 1003 |
3007 | 75.75 | 10/04/1990 | 2004 | 1002 |
3008 | 4723.00 | 10/05/1990 | 2006 | 1001 |
3010 | 1309.95 | 10/06/1990 | 2004 | 1002 |
3011 | 9891.88 | 10/06/1990 | 2006 | 1001 |
, snum , . snum , . , , snum . , , " ". 19.
: , , . -, . , , , , , , .
, SQL, , , . .
1.1
Snum | , (" ") |
Sname | |
City | () |
Comm |
1.2 :
Cnum | , |
Cname | |
City | () |
Rating | , . (). |
Snum | , ( ) |
1.3:
Onum | , |
Amt | |
Odate | |
Cnum | ( ) |
Snum | ( ) |
, , , , . , , , , . , , . SQL, .
|
|
. , , , .
SQL . , , .
SQL
1. ?
2. 4 ?
3. ? ?
4. ?
(. A .)
SQL:
SQL, , , , , SQL. . , . , . , SQL , . , SQL, 3.
SQL?
SQL , . , , , C. C, . , , , , . , , :
1. .
2. , , .
3. , -, .
4. , .
5. , 1.
6. , , 3.
(, C , , .)
SQL , . SQL , , .
ANSI?
, SQL ANSI ( ). SQL ANSI. , , IBM. SQL , , (Oracle), IBM SQL .
, SQL , ANSI , ( ANSI). . ANSI . ANSI , , ANSI, . , , . ANSI SQL . , ANSI . , , , ANSI. ANSI , .
|
|