data access: how visual basic communicates with a database or data store to retrieve, update, add, and delete data.
data access objects (dao): a com-based, microsoft programming interface used for data access. dao uses the jet database engine for data management, and uses open database connectivity direct (odbcdirect) to provide access to odbc databases. see also: component object model, open database connectivity, remote data objects.
data control: a control placed on a form and bound to a data source. it provides buttons that enable you to move through the data.
database management system (dbms): a software interface that handles user requests for database actions, and controls security, integrity, interactive querying, interactive data entry and updating, and independence of data in a database. it accepts requests from the application and instructs the operating system to transfer the appropriate data.
data environment designer: provides a graphical approach for generationg codeless activex data objects connections, commands, and recordsets from row-returning queries. connects to jet databases through a native ole db data provider and to other odbc-enabled desktop and client/server data sources with the microsoft ole db provider for odbc.
date function: returns the current date from the system clock.
dateadd function: returns a variant containing a date to which a specified time interval has been added. used to add or subtract a time interval from an existing date.
datediff function: returns a variant containing the number of time intervals between two specified dates.
datepart function: returns a specified part of a given date.
dateserial function: returns the date for a specific year, month, and day.
datevalue function: returns the date represented by a string argument.
day function: returns a whole number representing the day of the month for a specified date.
dblclick event: occurs when the user double-clicks a mouse button over an object.
ddb function: returns the depreciation of an asset for a specific period using the double-declining balance method.
deactivate event: occurs when a form is no longer the active window.
debug: to detect, locate, and correct logical or syntactical errors in a program's code.
default property: when an object is accessed, this property is used automatically if no property is specified. vb objects usually have a default property. for example, if you access a textbox without specifying a property, it will use the text property. for instance, x = txtname is the same as x = txtname.text.
deferred integrity: a conceptual protocol that assumes the success of a piece of work but checks its success later. writing a check at a store and receiving your merchandise, while the actual transfer of money occurs later, is an example of deferred integrity.
design time: term describing changes you make to your program through the vb ide when the program is not running. the opposite of run time. see also: run time.
dir function: returns the name of a file or directory that matches a specified pattern and file attribute. can also return the volume label of a drive.
distributed component object model (dcom): microsoft's counterpart to corba, dcom facilitates remote object distribution over networks and the internet. this distributed object technology provides additions to com. see also: component object model, common object request broker architecture.
distributed processing: spreads the functionality of a program across different machines. for example, ui code is on the client machine, data access components reside in an mts server, and the database is on another machine.
dockable: a window is docked when it's anchored to the edge of the host window instead of being able to move around freely.
doevents function: causes visual basic to yield execution so windows can process events.
dragdrop event: occurs when a drag-and-drop operation is completed as a result of dragging a control over a form or control and releasing the mouse button.
dragover event: occurs when a drag-and-drop operation is in progress.
dropdown event: occurs when the list portion of a combo box is about to drop down.
dynamic data exchange (dde): a mechanism supported by windows that enables two applications to exchange data continuously and automatically.
dynamic html (dhtml): html tag enhancements enabling web pages to function more like software. enables you to change html tags dynamically using a scripting language.
dynamic link library (dll): enables you to bind code to one of many executables at run time rather than at link time, creating an environment in which m
