........... command provides a window through which one can see the data of another table.

Question

Accepted Answer

The correct option is (3):
The **CREATE VIEW** command is the correct answer because a **VIEW** in SQL is fundamentally a virtual table based on the result-set of an SQL query. A view does not physically store any data itself; rather, it stores the query which, when executed, pulls data from the underlying *base table(s)*. This mechanism perfectly fits the description of providing a "window" through which one can see the data of another table. Views are powerful tools used for two primary purposes: simplifying complex query logic for end-users, and implementing security by restricting the columns and rows a specific user can access from the underlying tables.

The incorrect option is (1):
The **SELECT** command is a Data Manipulation Language (DML) command whose sole purpose is to retrieve data from one or more tables or views. While you use a `SELECT` statement to *look* at the data *through* the window, the `SELECT` command itself is not the instruction that *creates* or *provides* the permanent, named, virtual structure (the "window"). The question asks for the command that **provides** the window, which is a definitional action, not a retrieval action. A `SELECT` query is temporary, whereas a VIEW is a persistent database object.

The incorrect option is (2):
The **CREATE** command is too broad to be the specific answer. **CREATE** is a Data Definition Language (DDL) keyword used as a prefix for many commands, such as `CREATE TABLE`, `CREATE INDEX`, and `CREATE DATABASE`. Using just **CREATE** in this context is imprecise. For example, `CREATE TABLE` is used to build the permanent, physical structure that holds the data, not a derived virtual structure that merely provides a view into existing data. The complete and specific command for creating the described 'window' is essential, which is **CREATE VIEW**.

The incorrect option is (4):
This option, **All options are wrong**, is incorrect because option (3), **CREATE VIEW**, is the precise and correct SQL command for defining a virtual table that serves as a dynamic window to the data of other tables. In a database system, a view is the standard and widely accepted object that matches the conceptual description given in the question. Therefore, a valid command is present among the options.