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FireDAC.Stan.Option.TFDTxOptions.Isolation

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Delphi

property Isolation: TFDTxIsolation read FIsolation write SetIsolation  default xiReadCommitted;

C++

__property TFDTxIsolation Isolation = {read=FIsolation, write=SetIsolation, default=2};

Properties

Type Visibility Source Unit Parent
property published
FireDAC.Stan.Option.pas
FireDAC.Stan.Option.hpp
FireDAC.Stan.Option TFDTxOptions

Description

Specifies the transaction isolation level for the transactions managed by FireDAC.

Use the Isolation property to specify the transaction isolation level for the next transactions in the current session. Changing an isolation level does not affect a currently active transaction. The default value is xiReadCommitted

The Isolation property value is DBMS-independent and it is translated into a closer native DBMS isolation level.

Level 

Description 

xiUnspecified

Uses the default DBMS isolation level. 

xiDirtyRead

Allows the reading of uncommitted changes made to the database by other simultaneous transactions. Uncommitted changes are not permanent, and might be rolled back (undone) at any time. At this level, a transaction is least isolated from the effects of other transactions. 

xiReadCommitted

Allows the reading of committed (permanent) changes made to the database by other simultaneous transactions. This is the default value of the Isolation property. 

xiRepeatableRead

Allows a single, one-time reading of the database. The transaction cannot see any subsequent changes made by other simultaneous transactions. This isolation level guarantees that once a transaction reads a record, its view of that record does not change unless it makes a modification to the record itself. At this level, a transaction is most isolated from other transactions. 

See Also

Samples

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