Datasnap.Provider.TProviderOptions

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Delphi

type TProviderOptions = set of TProviderOption;

C++

typedef System::Set<TProviderOption, TProviderOption::poFetchBlobsOnDemand, TProviderOption::poUseQuoteChar> TProviderOptions;

Properties

Type Visibility Source Unit Parent
set
typedef
public
Datasnap.Provider.pas
Datasnap.Provider.hpp
Datasnap.Provider Datasnap.Provider

Description

TProviderOptions influences the type of information that is communicated between client datasets and provider components.

TProviderOptions is a set of TProviderOption values.

TProviderOption values are listed in the following table.



Value Meaning

poFetchBlobsOnDemand

BLOB fields are not included in data packets. Instead, client applications must request these values on an as-needed basis. If the client dataset's FetchOnDemand property is True, then the client requests these values automatically. Otherwise, the client application uses the FetchBlobs method to retrieve BLOB data.

poFetchDetailsOnDemand

When the provider represents the master of a master/detail relationship, nested detail values are not included in the data packet. Instead, client applications request these on an as-needed basis. If the client dataset's FetchOnDemand property is True, then the client requests these values automatically. Otherwise the client application uses the FetchDetails method to retrieve nested detail sets.

poIncFieldProps

The data packet includes the following field properties (where applicable): Alignment, DisplayLabel, DisplayWidth, Visible, DisplayFormat, EditFormat, MaxValue, MinValue, Currency, EditMask, DisplayValues.

poCascadeDeletes

Tells the server to delete detail records automatically when master table records are deleted. To use this option, the provider must represent the master of a master/detail relationship and the database must support cascaded deletes as part of its referential integrity settings.

poCascadeUpdates

Tells the server to automatically update detail records when master table key values are changed. To use this option, the provider must represent the master of a master/detail relationship and the database must support cascaded updates as part of its referential integrity settings.

poReadOnly

The client dataset cannot apply updates to the provider.

poAllowMultiRecordUpdates

Enables individual updates that affect multiple records. When poAllowMultiRecordUpdates is not included, updates that change multiple records are automatically aborted.

poDisableInserts

Clients cannot add new records. If the client tries to insert a record, an exception is raised. (This does not affect the client's ability to edit or delete records.)

poDisableEdits

Clients cannot modify existing data values. If the client tries to edit a field, an exception is raised. (This does not affect the client's ability to insert or delete records.)

poDisableDeletes

Clients cannot delete records. If the client tries to delete a record, an exception is raised. (This does not affect the client's ability to edit or insert records.)

poNoReset

Ignores the reset flag in calls to AS_GetRecords (TGetRecordsOption value of grReset).

poAutoRefresh

Refreshes the client dataset with current record values whenever it applies updates.

poPropogateChanges

Changes made in a BeforeUpdateRecord or AfterUpdateRecord event handler are sent back to the client and merged into the client dataset.

poAllowCommandText

Enables the client to override the provider's dataset by replacing its associated SQL text or the name of its stored procedure or table. These overrides are supplied to the GetRecords or Execute method.

poRetainServerOrder

Signals that the client should not attempt to re-establish the default order by sorting the records in the data packet. This prevents the client from changing the record order because, for example, it is unable to duplicate the locale on the server.

poUseQuoteChar

Specifies that the quotation mark (“) used by the SQL provider will also be used to quote SQL identifiers in the SQL queries created by the provider. This option is True by default; set it to False to eliminate the quotes.



See Also