. , , , .. , , . , , T1, 2 , 1. , .
. : READ UNCOMMITTED ( ) < READ COMMITTED ( ) < REPEATABLE READ ( ) < SERIALIZABLE ( ). . , PARADOX (IDE Borland Builder) DIRTY READ, READ COMMITED REPEATABLE READ.
( ), . , , . , :
1. . , 1 A. 1 2 A. 2 ROLLBACK (, ). 1 , . . , . , 1 . , . : 1 ;
2. . , 1 , 2 , 1 . 2 , , ( 1 ); 1 2. 1 A. 2 A. , 2 "" ( , 2 ). ( ). "" , 1, A, A ( A 1). : 1 ;
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3. . , 1 A. 1 2 A COMMIT. 1 A . , 1 A. , , . : 1 ;
4. . , 1 , (, ). , 2 , . 1 , , "" . , . -, "" . ( ) , .
:
| READ UNCOMMITTED | |||
| READ COMMITTED | |||
| REPEATABLE READ | |||
| SERIALIZABLE |
. , . , , . , . . , . , , .
