Issues with combining heterogeneous data sources under a single query interface have existed for some time.

Difficulties also arise in constructing data warehouses when one has only a query interface to summary data sources and no access to the full data.

First, it uses an interactive questionnaire-based query interface to guide users to provide the most important information about their situations.

Access also includes a query interface, forms to display and enter data, and reports for printing.

Where with respect to data ware house there are: may be limitation of query interface, inconsistence output and rapid change in data by admin without any notice.

Two query interfaces are offered:

Unlike the better-known ODBC, DataLens did not use SQL in the query interface.

It also supports a generalized query interface, which allows you to query derived quantities such as volume or surface area.

A heterogeneous database system is an automated (or semi-automated) system for the integration of heterogeneous, disparate database management systems to present a user with a single, unified query interface.

While many of the ontologies queriable by the OLS are available online, each has its own query interface and output format.