|Lesson 8|| Using OPENQUERY |
|Objective|| Use the OPENQUERY remote data function to access remote data.|
OPENQUERY function is used in very much the same way as the
OPENROWSET function is, but it uses a server that is already linked. The
OPENQUERY function uses the syntax shown in the following display.
FROM OPENQUERY(as400, '
WHERE column = ''value''
In the previous lesson, you used the
OPENROWSET function to access the Timesheets table using the parameters shown below:
You could use
OPENQUERY function for the same purpose, as long as the Boston server is already linked, with the following Transact-SQL statement:
FROM OPENQUERY('Boston','SELECT * FROM Timesheets') AS t
Notice that the only difference in the way the above query is structured from the
OPENROWSET query is that you do not have to specify the connection parameters for the OLE DB data source. You already did that when you created the linked server.
In the next lesson, we will review the information covered in this module.
Distributed data sources pull in data from other SQL Server databases, other SQL Servers, other database platforms (e.g., Microsoft Access, Oracle, Foxpro), or applications (e.g., Excel) using openquery() and other distributed functions.