Importing and Exporting Data

Importing data is the process of retrieving data from sources external to Microsoft® SQL Server™ (for example, an ASCII text file) and inserting it into SQL Server tables. Exporting data is the process of extracting data from an instance of SQL Server into some user-specified format (for example, copying the contents of a SQL Server table to a Microsoft Access database).

Importing data from an external data source into an instance of SQL Server is likely to be the first step you perform after setting up your database. After data has been imported into your SQL Server database, you can start to work with the database.

Importing data into an instance of SQL Server can be a one-time occurrence (for example, migrating data from another database system to an instance of SQL Server). After the initial migration is complete, the SQL Server database is used directly for all data-related tasks, rather than the original system. No further data imports are required.

Importing data can also be an ongoing task. For example, a new SQL Server database is created for executive reporting purposes, but the data resides in legacy systems updated from a large number of business applications. In this case, you can copy new or updated data from the legacy system to an instance of SQL Server on a daily or weekly basis.

Usually, exporting data is a less frequent occurrence. SQL Server provides tools and features that allow applications, such as Access or Microsoft Excel, to connect and manipulate data directly, rather than having to copy all the data from an instance of SQL Server to the tool before manipulating it. However, data may need to be exported from an instance of SQL Server regularly. In this case, the data can be exported to a text file and then read by the application. Alternatively, you can copy data on an ad hoc basis. For example, you can extract data from an instance of SQL Server into an Excel spreadsheet running on a portable computer and take the computer on a business trip.

SQL Server provides tools for importing and exporting data to and from data sources, including text files, ODBC data sources (such as Oracle databases), OLE DB data sources (such as other instances of SQL Server), ASCII text files, and Excel spreadsheets.

Additionally, SQL Server replication allows data to be distributed across an enterprise, copying data between locations and synchronizing changes automatically between different copies of data.