Developer Reference : Data Access Methods : ActiveX Controls Guide : Properties, Methods, and Events By Category
 
Properties, Methods, and Events By Category
This chapter lists all properties, methods, and events designed for Zen according to their functions, contained in the following sections:
•Introduction to ActiveX Properties, Methods, and Events
•Retrieving Sets of Records
•File Handling
•Data Dictionary Methods
•Accessing Fields in a Record
•Inserting, Updating, and Deleting Records
•Retrieving Individual Records
•Optimization and Debugging
Introduction to ActiveX Properties, Methods, and Events
Properties, methods, and events are the three types of functions you can apply to an ActiveX control.
The distinction between a property and a method is not always obvious but can be clarified by the following statements:
Let variable = method is generally legal syntax. Let method = variable is not.
Both Let property = variable and Let variable = property, however, are legal constructs.
An event is a function triggered within your application by an ActiveX control to which you can respond.
Note The properties, methods, and events listed in this chapter include those designed for the ActiveX access method. In addition, you may see other properties, methods, and events associated with a control which are provided by the development tool (for example, Visual Basic). Consult the documentation of your specific development tool for information.
Retrieving Sets of Records
This section lists the properties, methods, and events which you can use to retrieve sets of records.
Properties and Methods
 
Table 22 Properties and Methods for Extended Operations 
Property or Method
Description
Enables or disables automatic caching of extended fetch data sets.
Determines the maximum number of records which may be skipped in processing a single extended fetch operation using SelectedRecords criteria.
Determines the maximum number of rows to be returned by a single extended fetch operation.
Enables or disables a dialog box allowing the user to cancel a sequence of single extended fetch operations.
Determines the current column for an extended fetch result set.
Specifies the name of the current column in an extended fetch result set. Default is the name of the field assigned to the column.
Returns the total number of columns in an extended fetch result set.
Enables or disables extended fetch properties and methods for a data source.
Selects the text in the VATextBox when the text box receives focus.
Performs an extended fetch beginning at the current cursor position and proceeding forward along the current index path.
Performs an extended fetch beginning at the current cursor position and proceeding backwards along the current index path.
Determines whether the record set results of the next extended fetch operation performed will include the current record or will begin with the subsequent record.
Allocates extended fetch parameters prior to invoking an extended fetch method after changing the SelectedFields or SelectedRecords criteria or establishing new current positioning in the file.
Specifies the size of the data buffer to use for extended fetch operations.
Sets or returns the current row in an extended fetch result set. Used to access the result set from an extended fetch method or to navigate rows which meet the search criteria.
Returns a field value from a specified Row and Column in a extended fetch result set.
Returns the physical position of the record in the current row of an extended fetch result set.
Returns the number of valid rows of data in an extended fetch result set.
Specifies which fields to use as columns in an extended fetch result set. Default is an empty list, indicating that all fields should be included.
Specifies record selection criteria for the records to be returned in an extended fetch result set. The default is an empty list, indicating that all records should be included.
Displays the property setting dialog box for the Selected Fields property.
Displays the property setting dialog box for the Selected Records property.
Performs an extended fetch beginning at the current position and proceeding forward in physical record order.
Performs an extended fetch beginning at the current cursor position and proceeding backwards in physical record order.
Events
 
Table 23 Events for Extended Operations 
Event
Description
Fires when an extended fetch operation is completed. Returns the number of rows and number of columns of data contained in the returned data buffer.
File Handling
This section lists the properties and methods which you can use to perform file handling.
Properties and Methods
 
Table 24 Properties and Methods for File Handling 
Property or Method
Description
Enables or disables automatic caching of extended fetch data sets.
Closes the file associated with the control.
Returns or sets the length in bytes of the record data buffer used for single-record operations on the file.
Attaches the VAccess control to a specific set of data definition files.
Returns the Zen file version.
Attempts to insert the current data buffer as a new record.
Sets or returns the drive, path, and file name of the table associated with the selected VAccess control.
Attempts to open the file associated with the control.
Sets or returns the open mode of the file associated with the control.
Specifies a Zen owner name to be used when trying to open the file associated with the VAccess control.
Sets or returns the page size of the Zen data file.
Sets the owner name of a file.
Retrieves current file status information from the file associated with the control.
Indicates which table will be associated with the control.
Returns the number of records contained in the Zen file associated with the VAccess control.
Data Dictionary Methods
This section lists the properties and methods which you can use for data dictionary methods.
Properties and Methods
 
Table 25 Properties and Methods for Data Dictionary Handling  
Property or Method
Description
Adds Indexes to the DDF file and to the corresponding Zen file.
Adds the current table to the current data dictionary.
Adds a new table to the current VAccess control memory image.
Clears the field information in the VAccess memory image for the current table.
Clears the index information in the VAccess memory image for the current table.
Creates a new, empty set of DDF files in the current location.
Adds a table definition to the dictionary and creates an empty data file.
Removes an index from the current Zen data file and from the data dictionary definition for the current table.
Removes an index from the current Zen data file and from the data dictionary definition for the current table while maintaining the ordering of the existing indexes.
Drops the current table from the data dictionary.
Reads field comments into the VAccess memory image from the COMMENT.DDF file.
Specifies whether or not the VAccess should use the true indexes of the file or the indexes as specified in the DDF.
Changes the table location of the current table and optionally writes the new location to the DDF.
Changes the name of the current table and optionally writes the new name to the DDF.
Sets the drive and path on which the DDF files associated with this control reside.
Sets the Btrieve owner name for the dictionary files to something other than the default owner name (..SC….) and security level (allow read-only access).
Sets the owner name used for opening dictionary files and determines whether or not a dictionary can be successfully opened and updated using the given owner name.
Determines whether or not updates to the data dictionary tables will take place within a transaction. Accepts or returns a boolean value.
Sets or returns a variant array containing information on the fields of the current table.
Returns the list of tables defined in the current dictionary as a two-dimensional variant array.
Sets or returns a variant array containing information on the indexes of the current table.
Sets or returns the drive, path, and file name of the Zen file associated with this control.
Determines whether the VAccess control will use DDF files for metadata or whether it will use internal states and/or persisted properties for metadata.
Indicates which table, from the set of all tables defined in the current DDF set, will be associated with the control.
Accessing Fields in a Record
This section lists the properties and methods which you can use to access fields in a record.
Properties and Methods
 
Table 26 Properties and Methods for Accessing Fields in a Record 
Property or Method
Description
Sets or returns a variant array containing information on the fields of the current table.
Sets or returns the total number of fields defined for the associated file.
Sets or returns the value of the field specified for the current record in memory or the current row of an extended fetch record set.
Returns the value of a field in the current record formatted using the specified format string.
Converts data stored in alphanumeric fields between ANSI and OEM character sets.
Inserting, Updating, and Deleting Records
This section lists the properties, methods, and events which you can use to insert, update, and delete records.
Properties and Methods
 
Table 27 Properties and Methods for Inserting, Updating, and Deleting Records 
Property or Method
Description
Sets or returns the contents of a control’s current record buffer.
Clears the contents of the data and index buffers of the current record in memory.
Deletes the current record.
Inserts the record in memory as a new record in the file.
Forces repainting of a bound control.
Begins, ends, or aborts a transaction.
Unlocks locked records.
Updates the current record with the record image in memory.
Events
 
Table 28 Events for Inserting, Updating, and Deleting Records 
Event
Description
Fires before any record operation takes place on the associated table.
Retrieving Individual Records
This section lists the properties, methods, and events which you can use to retrieve individual records.
Properties and Methods
 
Table 29 Properties and Methods for Retrieving Individual Records 
Property or Method
Description
Sets or returns the contents of a control’s current record buffer.
Returns a record using its physical position in the file.
Returns a record by an exact match to the current index.
Returns the first record in the current index path.
Returns the first record greater than the current key value in the current index path.
Returns the first record greater than or equal to the current key value in the current index path.
Returns the last record in the current index path.
Returns the last record in the current index path containing a value less than the value specified for the key fields.
Returns the last record in the current index path containing a value less than or equal to the value specified for the key fields
Returns the next record in the current index path.
Returns the previous record in the current index path
Returns the total number of segments contained in the specified index of the file associated with the VAccess control.
Returns the current index number for the table associated with the VAccess control.
Sets the record to retrieve at the specified relative position along the currently selected index path in the associated table.
Returns the value of the physical position of the current record in the table associated with the VAccess control.
Determines whether the VAccess control will use DDF files for metadata or whether it will use internal states and/or persisted properties for metadata.
Returns the first record in physical record storage order.
Returns the last record in physical record storage order.
Returns the next record in physical record storage order.
Returns the previous record in physical record storage order.
Events
 
Table 30 Events for Retrieving Individual Records 
Property or Method
Description
Fires before any record operation takes place on the associated table.
Optimization and Debugging
This section lists the properties and methods which you can use to perform optimization and debugging functions.
Properties and Methods
 
Table 31 Properties and Methods for Optimization and Debugging 
Property or Method
Description
Enables or disables event firing for the VAccess control.
Restricts the records available to the control, and maintains relational positioning in the associated table relative to field values of another VAccess control.
Sets or Returns the Session ID the client will use.
Returns the Zen status from the last Zen operation on the file associated with the VAccess control.
Displays a task-modal message box at run time if set to a non-zero number.
Selects or disables Debug mode error checking for the controls.