Visual basic database: – A database can be viewed as a set interrelated data item. Database management deals with storage, retrieval, and editing of data with in data base. The main function of data base are security and validations of data items for data base.
Visual basic makes a simple to handle data base by supplying a variety of tools and methods for data management. Visual basic has a fledged database engine called jet. This engine contains virtually all database function that many application would need.
Visual basic also provide a powerful and easy to use from end development environment for database environment. Visual basic support many popular database format like MS-Access, Dbase, FoxPro, Oracle 8, MS SQL server 7.0 etc. using this we can manipulate data base in different format. To use database file, we must understand the basic terminology of relation database.
- Database: – A database is a collection of interrelated data. A database contains a table. Each row in a table represents the data for one item, person or transection and is called a record each column in table in used to store a different element of data, such as account number, name, address or any numeric constant and is called field.
- Database engine: – it is a program that organizes files and retrieves from the table.
- Record set: – A record set is an object that content a set of record from the database. Record set come in different types, these are often called a curser type. A cursor is another name for a record set, and when we decide which records we want to see, we also get in choose the curser type. There are five types of record set used in database. They are table type record set, Dynaset type record set, snapshot type record set, dynamic type record set and forward only type record set.
- Table type record set: – The table type record set object is a set of object that represent a single table which can be used to add, change or delete record. They are fastest type of record set.
- Dynaset type record set: – The dynaset type record set object is a set of record that represents a table or attached table or the result of queries containing fields from one or more table. A dynaset enable us to update data from. More than one table.
- Snapshot type record set: – This type of record set can refer to any table, attached table or query. A snapshot cannot be updated and does not reflect any changes made by user.
- Dynamic type record set: – This type of record set represent a query result from one or more base table in which we can add, change or delete record from a row returning query. Further, records that other users add, delete or edit in the base table also appear in the record set.
- Forward only type record set: – This type of record set is identical to the snapshot record set except we can only scroll forward through its record. This improve performance in situation where we only need to make a single pass through a result set.