DB2


- 2


SQL;

SELECT _ FROM S

WHERE EXISTS

(SELECT _ FROM SP

WHERE SP.HOMEP_ =

S._);

( ) t, .

SQL:

SELECT _ FROM S

WHERE NOT EXISTS

(SELECT _ FROM SP

WHERE SP.HOMEP_ =

S. _);

t,

, t ,

, - t, .

SQL:

SELECT S.*, SP.*

FROM S, SP;

theta , =, =,

>, >= . . Theta-ce Y t

, , t. X theta t. Y. Y , theta . Y . , theta- , . . , .

. Theta- . , , SELECT SQL.

SQL:

SELECT *

FROM S

WHERE Ġ = '';

, . . , , , , .




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