SQL command used to add a new column in an existing table is :

Question

Accepted Answer

The correct option is (1):
The **ALTER** command is the foundational statement in Structured Query Language (SQL) used for modifying the structure, or schema, of an existing database object, such as a table. It is a key command within the Data Definition Language (DDL) subset of SQL, which focuses on database structure rather than the data itself. To add a new column to a table, the correct syntax explicitly uses the `ALTER TABLE` command followed by the `ADD` keyword. Therefore, `ALTER` is the correct and most encompassing command for initiating any structural modification, including the addition of a new column, to an existing table.

The incorrect option is (2):
**UPDATE** is classified as a Data Manipulation Language (DML) command, and its purpose is solely to modify the *data* or *records* that are already stored within a table. It allows you to change the values in existing rows that match a specified condition defined by the `WHERE` clause. It is not designed to alter the table's fundamental structure, which includes adding, deleting, or renaming columns. The `UPDATE` command is a row-level operation and cannot modify the table's column definitions.

The incorrect option is (3):
The term **CHANGE** is sometimes used in specific SQL dialects, such as MySQL, but it functions primarily as a *subcommand* within the main `ALTER TABLE` statement. Furthermore, where it is used, it is generally employed to rename an *existing* column or to modify its definition (like its data type). It is not the universal or primary command used for adding a brand-new column. In most standard SQL environments, the correct subcommand for this specific operation is **ADD**.

The incorrect option is (4):
**ADD NEW** is not a valid or standard reserved keyword combination in SQL. Although the operation logically describes the action (adding a new column), the correct SQL syntax requires the **ADD** keyword to be used as a subcommand immediately following the primary **ALTER TABLE** command. Relying on descriptive phrases rather than the precise technical keywords will result in a syntax error, making this option incorrect.