Presentation on theme: "Basics of Database Programming with VB6"— Presentation transcript:
1Basics of Database Programming with VB6 By: Mr. Carl Michael L. Morados
2What is a database?Database – a collection of related data or information, that is stored, modified and transmitted.Personal InfoStudent DatabasePaymentsGrades
3Structure of a Database Tables – collection of related informationRecords –single piece of informationFields – smallest unit of information that is useful to users.
4Structure of a Database RecordStudent Information SheetName:Address:Contact No.:FieldsTable
5Visual Basic and Database Front End – the user interface, which the program uses to interact with the user.Back End – the database, where all data coming from the user are saved, to be retrieved later.
6Visual Basic and Database Database DriverADO ObjectThe user interacts withthe program by userinterface or screens.(Database Application)(Visual Basic)
7What are database drivers? It allows different programming languages to communicate or get information from different data sources.
8Using the ADODC ObjectADODC (ActiveX Data Object) – an object used to connect a Visual Basic program to a database.ADODC Object on thetoolboxADODC Object whenplaced on the form
9Inserting the ADODC Object Go to Project menu, then choose Components. (or right click on the toolbox)When the components dialog appears, choose Microsoft ADO Data Control 6.0.
10Inserting the ADODC Object Components Dialog Window
11Connecting the ADODC to a database Straight ConnectionSetting of the Database Provider and directly specifying the path of the database (location).Using ODBC (Open Database Connectivity)Creating a Data Source Name (DSN) using the ODBC Administrator of Windows
12Steps in Connecting ADODC Right Click on the ADO ObjectConnect the ADO by using the Connection String or ODBC Data Sources
13Steps in Connecting ADODC Choose the correct databaseprovider.
14Steps in Connecting ADODC Specify the correct path ofthe databaseTest the connection if the ADODCwhere able to communicate withthe data source.
15Steps in Connecting ADODC Specify how the ADODC willconnect to the table.
16Structure of an ADODC commands <adodc name>.RECORDSET.<method>The Name of the adodc objectRefers to the tableobjectMethods that canbe done to a table
17Types of ADODC methods Record Operations Addnew – used to add records to the table.Delete – used to delete records from the table.Update – used to save records to the table.CancelUpdate – cancels any record-related operations.
18Types of ADODC commands Record NavigationFind <parameters> - used to find or search records, based on key fields.Movefirst – go to the first record.Movelast – go to the last record.Movenext – go to the next record.Moveprevious – go to the previous record.Move(record no.) – go to a specified record no.
19Types of ADODC commands Record CountersRecordCount – returns the number of records on the tableEOF – End of File, returns True if the record pointer reaches the end of the table.BOF – Beginning of File, returns True if the record pointer reaches the beginning of the table
20Finding Records FIND “[key field] like ‘comparing value’ e.g. adoSTUD.RECORDSET.FIND “[LName] like ‘Locsin’”In finding records, always REFRESH the table first. to complete the code:adoSTUD.REFRESH
21Using the SQL Statements SQL (Structured Query Language) – is composed of series of statements and clauses, which, when combined, perform different actions.Select Queries – returns a specific set of records, based on criteriaAction Queries – performs actions such as deleting, adding or updating records.
22Basic Structure of Select SELECT <fields> FROM <tablename> [<where> <condition> <order by>]e.g.Select * from StudInfo