VirtualDAC

TCustomDADataSet Members

TCustomDADataSet class overview.

Properties

Name Description

BaseSQL

Used to return SQL text without any changes performed by AddWhere, SetOrderBy, and FilterSQL.

CachedUpdates (inherited from TMemDataSet)

Used to enable or disable the use of cached updates for a dataset.

Conditions

Used to add WHERE conditions to a query

Connection

Used to specify a connection object to use to connect to a data store.

DataTypeMap

Used to set data type mapping rules

Debug

Used to display the statement that is being executed and the values and types of its parameters.

DetailFields

Used to specify the fields that correspond to the foreign key fields from MasterFields when building master/detail relationship.

Disconnected

Used to keep dataset opened after connection is closed.

FetchRows

Used to define the number of rows to be transferred across the network at the same time.

FilterSQL

Used to change the WHERE clause of SELECT statement and reopen a query.

FinalSQL

Used to return SQL text with all changes performed by AddWhere, SetOrderBy, and FilterSQL, and with expanded macros.

IndexFieldNames (inherited from TMemDataSet)

Used to get or set the list of fields on which the recordset is sorted.

IsQuery

Used to check whether SQL statement returns rows.

KeyExclusive (inherited from TMemDataSet)

Specifies the upper and lower boundaries for a range.

KeyFields

Used to build SQL statements for the SQLDelete, SQLInsert, and SQLUpdate properties if they were empty before updating the database.

LocalConstraints (inherited from TMemDataSet)

Used to avoid setting the Required property of a TField component for NOT NULL fields at the time of opening TMemDataSet.

LocalUpdate (inherited from TMemDataSet)

Used to prevent implicit update of rows on database server.

MacroCount

Used to get the number of macros associated with the Macros property.

Macros

Makes it possible to change SQL queries easily.

MasterFields

Used to specify the names of one or more fields that are used as foreign keys for dataset when establishing detail/master relationship between it and the dataset specified in MasterSource.

MasterSource

Used to specify the data source component which binds current dataset to the master one.

Options

Used to specify the behaviour of TCustomDADataSet object.

ParamCheck

Used to specify whether parameters for the Params property are generated automatically after the SQL property was changed.

ParamCount

Used to indicate how many parameters are there in the Params property.

Params

Used to view and set parameter names, values, and data types dynamically.

Prepared (inherited from TMemDataSet)

Determines whether a query is prepared for execution or not.

Ranged (inherited from TMemDataSet)

Indicates whether a range is applied to a dataset.

ReadOnly

Used to prevent users from updating, inserting, or deleting data in the dataset.

RefreshOptions

Used to indicate when the editing record is refreshed.

RowsAffected

Used to indicate the number of rows which were inserted, updated, or deleted during the last query operation.

SQL

Used to provide a SQL statement that a query component executes when its Open method is called.

SQLDelete

Used to specify a SQL statement that will be used when applying a deletion to a record.

SQLInsert

Used to specify the SQL statement that will be used when applying an insertion to a dataset.

SQLLock

Used to specify a SQL statement that will be used to perform a record lock.

SQLRecCount

Used to specify the SQL statement that is used to get the record count when opening a dataset.

SQLRefresh

Used to specify a SQL statement that will be used to refresh current record by calling the TCustomDADataSet.RefreshRecord procedure.

SQLUpdate

Used to specify a SQL statement that will be used when applying an update to a dataset.

UniDirectional

Used if an application does not need bidirectional access to records in the result set.

UpdateRecordTypes (inherited from TMemDataSet)

Used to indicate the update status for the current record when cached updates are enabled.

UpdatesPending (inherited from TMemDataSet)

Used to check the status of the cached updates buffer.

Methods

Name Description

AddWhere

Adds condition to the WHERE clause of SELECT statement in the SQL property.

ApplyRange (inherited from TMemDataSet)

Applies a range to the dataset.

ApplyUpdates (inherited from TMemDataSet)

Overloaded. Writes dataset's pending cached updates to a database.

BreakExec

Breaks execution of the SQL statement on the server.

CancelRange (inherited from TMemDataSet)

Removes any ranges currently in effect for a dataset.

CancelUpdates (inherited from TMemDataSet)

Clears all pending cached updates from cache and restores dataset in its prior state.

CloneCursor

Shares data from another dataset.

CommitUpdates (inherited from TMemDataSet)

Clears the cached updates buffer.

CreateBlobStream

Used to obtain a stream for reading data from or writing data to a BLOB field, specified by the Field parameter.

DeferredPost (inherited from TMemDataSet)

Makes permanent changes to the database server.

DeleteWhere

Removes WHERE clause from the SQL property and assigns the BaseSQL property.

EditRangeEnd (inherited from TMemDataSet)

Enables changing the ending value for an existing range.

EditRangeStart (inherited from TMemDataSet)

Enables changing the starting value for an existing range.

Execute

Overloaded. Executes a SQL statement on the server.

Executing

Indicates whether SQL statement is still being executed.

Fetched

Used to find out whether TCustomDADataSet has fetched all rows.

Fetching

Used to learn whether TCustomDADataSet is still fetching rows.

FetchingAll

Used to learn whether TCustomDADataSet is fetching all rows to the end.

FindKey

Searches for a record which contains specified field values.

FindNearest

Moves the cursor to a specific record or to the first record in the dataset that matches or is greater than the values specified in the KeyValues parameter.

FindParam

Determines if a parameter with the specified name exists in a dataset.

GetBlob (inherited from TMemDataSet)

Overloaded. Retrieves TBlob object for a field or current record when only its name or the field itself is known.

GetDataType

Returns internal field types defined in the MemData and accompanying modules.

GetFieldObject

Returns a multireference shared object from field.

GetFieldPrecision

Retrieves the precision of a number field.

GetFieldScale

Retrieves the scale of a number field.

GetKeyFieldNames

Provides a list of available key field names.

GetOrderBy

Retrieves an ORDER BY clause from a SQL statement.

GotoCurrent

Sets the current record in this dataset similar to the current record in another dataset.

Locate (inherited from TMemDataSet)

Overloaded. Searches a dataset for a specific record and positions the cursor on it.

LocateEx (inherited from TMemDataSet)

Overloaded. Excludes features that don't need to be included to the TMemDataSet.Locate method of TDataSet.

Lock

Locks the current record.

MacroByName

Finds a macro with the specified name.

ParamByName

Sets or uses parameter information for a specific parameter based on its name.

Prepare

Allocates, opens, and parses cursor for a query.

RefreshRecord

Actualizes field values for the current record.

RestoreSQL

Restores the SQL property modified by AddWhere and SetOrderBy.

RestoreUpdates (inherited from TMemDataSet)

Marks all records in the cache of updates as unapplied.

RevertRecord (inherited from TMemDataSet)

Cancels changes made to the current record when cached updates are enabled.

SaveSQL

Saves the SQL property value to BaseSQL.

SaveToXML (inherited from TMemDataSet)

Overloaded. Saves the current dataset data to a file or a stream in the XML format compatible with ADO format.

SetOrderBy

Builds an ORDER BY clause of a SELECT statement.

SetRange (inherited from TMemDataSet)

Sets the starting and ending values of a range, and applies it.

SetRangeEnd (inherited from TMemDataSet)

Indicates that subsequent assignments to field values specify the end of the range of rows to include in the dataset.

SetRangeStart (inherited from TMemDataSet)

Indicates that subsequent assignments to field values specify the start of the range of rows to include in the dataset.

SQLSaved

Determines if the SQL property value was saved to the BaseSQL property.

UnLock

Releases a record lock.

UnPrepare (inherited from TMemDataSet)

Frees the resources allocated for a previously prepared query on the server and client sides.

UpdateResult (inherited from TMemDataSet)

Reads the status of the latest call to the ApplyUpdates method while cached updates are enabled.

UpdateStatus (inherited from TMemDataSet)

Indicates the current update status for the dataset when cached updates are enabled.

Events

Name Description

AfterExecute

Occurs after a component has executed a query to database.

AfterFetch

Occurs after dataset finishes fetching data from server.

AfterUpdateExecute

Occurs after executing insert, delete, update, lock and refresh operations.

BeforeFetch

Occurs before dataset is going to fetch block of records from the server.

BeforeUpdateExecute

Occurs before executing insert, delete, update, lock, and refresh operations.

OnUpdateError (inherited from TMemDataSet)

Occurs when an exception is generated while cached updates are applied to a database.

OnUpdateRecord (inherited from TMemDataSet)

Occurs when a single update component can not handle the updates.
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