visual basic database access

Visual Basic Database Access BICS546 Microsoft Universal Data Access • OLE DB: The OLE database protocol – Allows a program to access information in any type of data source, and it is the basis for ADO. – Data provider: databases, spreadsheets, etc. • ADO: ActiveX Data Objects – An Interface for OLE DB. – Allow programmers to use a standard set of objects to refer to any OLE DB data source. • ODBC: Open Database Connectivity – A driver manager – Used for relational databases Program ActiveX Data Objects OLE DB Provider Data Source OLE DB Provider ODBC ODBC Data Source Using ODBC • Three types of data source names – User DSN: usable only by you and only on the machine currently using. – System DSN: Any one using the machine can use. – File DSN: Can be copied and used by other computers with the same driver installed. Visual Basic Database Tools • Visual Data Manager • Data Environments • Data Views • Data Report Designer • Data Projects Visual Data Manager • Add-Ins/Visual Data Manager • Supports: Access, dBase, FoxPro, Paradox, ODBC, Text files. • Creating new database • Managing existing database • Query Builder, Form Wizard • DAO Data Environments • Project/More ActiveX Designer/Data Environment • Data Environments are designed to be the basis of design-time and run-time data access. They make data available to any forms and modules in your application. Data Environments at Design Time • Right Click Connection1 – Click Properties to set up database connection – Click Add Command to choose record source. • Drag and drop fields from Command1 to form. Text box properties: – Data Source: Data Environment1 – Data Member: Command1 (Note: Data environment can support many command objects) – Data Field Data Environments at Run Time • Access command object’s Recordset object and Recordset object’s methods. • Recordset’s name: rs+command name. – Ex. rsCommand1 • Properties: – EOF, BOF, RecordCount • Methods: – MoveFirst, MoveLast, MoveNext, MovePrevious Data Environment Code Example DataEnvironment1.rsCommand1.MoveNext IF DataEnvironment1.rsCommand1.EOF THEN DataEnvironment1.rsCommand1.MoveLast END IF [...]... Projects • VB projects come with built-in Data Environments and Data Report Designer Using Databases in VB • Three VB database objects: – DAO, RDO, ADO • Two ways to work with these objects: – VB Data controls, data-bound controls – Programming objects DAO • Support the Jet database • DAO data control – – – – Database property RecordSource property: tables, queries, SQL statement RecordSet Type Property:...Data Views • View/Data View Window • An overview of the database objects you have in a project, such as Data Environments, connections, data links Data Report Designer • Project/Add Data Report • Features of Data Report Designer – Drag and Drop fields from... Project/Components/Microsoft ADO 6.0 • Double Click ADO to insert ADO • Right Click and select ADODC Properties – General : Source of Connection – RecordSource: • 1 – adCmdText: SQL statement • 2 – adCmdTable: Table in the database • 4 - adCmdStoredProc ADO Properties • BOF Action, EOF Action • Command TimeOut: Amount of time in seconds the ADO control will allow for commands to be executed on the server • ConnectionString... until updates are actually applied • BatchOptimistic: All changes be submitted at one time • Pessimistic: Lock the table the entire time that the recordset is open Cursor Mode Property • Determines the access rights of the user – – – – Read Write ReadWrite ShareDenyRead: Deny other from opening connections with read permissions – ShareDenyWrite – ShareExclusive – ShareDenyNone: Prevent others from opening . Visual Basic Database Access BICS546 Microsoft Universal Data Access • OLE DB: The OLE database protocol – Allows a program to access information in any type. installed. Visual Basic Database Tools • Visual Data Manager • Data Environments • Data Views • Data Report Designer • Data Projects Visual Data Manager • Add-Ins /Visual Data Manager • Supports: Access, . Using Databases in VB • Three VB database objects: – DAO, RDO, ADO • Two ways to work with these objects: – VB Data controls, data-bound controls – Programming objects DAO • Support the Jet database • DAO