OPENQUERY AND OPENROWSET IN SQL SERVER

OPENQUERY: Used to execute the query passed on the linked server.

Syntax: OPENQUERY (Linked_server_identifier, query).

It can also be refernced from a FROM clause of selecte query.

e.g. Select * from OPENQUERY (Oracleserver, ‘select fname, FROM Employee);

OPENROWSET: Used to access tables in a linked server. It can be used one time for accessing remote data by using OLE DB. It includes all the information required to access the remote data.

Syntax:
OPENROWSET
( { 'provider_name' , { 'datasource' ; 'user_id' ; 'password'
| 'provider_string' }
, { [ catalog. ] [ schema. ] object
| 'query'
}
| BULK 'data_file' ,
{ FORMATFILE = 'format_file_path' [ ]
| SINGLE_BLOB | SINGLE_CLOB | SINGLE_NCLOB }
} )