Microsoft Access is very capable of interfacing with data from other sources. It can use data from any OLE DB or Open Database Connectivity (ODBC) data source, as well as data from FoxPro, dBASE, Paradox, Lotus, Excel, and many other sources. In this hour, you will learn how to interface with external data sources other than OLE DB and ODBC data sources.
External data is data that is stored outside the current database. External data may be data that you store in another Microsoft Access database, or it might be data that you store in a multitude of other file formats?including Indexed Sequential Access Method (ISAM), spreadsheet, ASCII, and more. This hour focuses on accessing data sources other than ODBC and OLEDB data sources. Other, more advanced, books, including Alison Balter's Mastering Access 2002 Enterprise Development (Sams Publishing), cover the process of accessing data stored in these data sources.
Access is an excellent front-end product, which means that it provides a powerful and effective means of presenting data?even data from external sources. You might opt to store data in places other than Access for many reasons. You can most effectively manage large databases, for example, on a back-end database server such as Microsoft SQL Server. You might store data in a FoxPro, dBASE, or Paradox file format because a legacy application written in one of those environments is using the data. You might download text data from a mainframe or midrange computer. Regardless of the reason the data is stored in another format, it is necessary that you understand how to manipulate this external data in Access applications. With the capability to access data from other sources, you can create queries, forms, and reports.
When you're accessing external data, you have two choices: You can import the data into an Access database or you can access the data by linking to it from an Access database. Importing the data is the optimum route (except with ODBC data sources), but it is not always possible. If you can't import external data, you should link to external files because Microsoft Access maintains a lot of information about these linked files. This optimizes performance when manipulating the external files.
In this hour you will accomplish the following tasks:
Gain an understanding of importing versus linking
Learn how to export to various file formats
Learn how to import from various file formats
Learn how to link to various file formats
Learn how to work with the Linked Table Manager