Which SQL command correctly adds a new FEES column to the TEACHER table?

Concept

A table schema defines its columns and their data types. SQL changes this structure with a data-definition statement rather than with statements that operate on row values.

The general pattern for adding one column is ALTER TABLE <table_name> ADD [COLUMN] <column_name> <data_type>; The word COLUMN is accepted in common dialects such as MySQL and PostgreSQL.

Application

1. Identify the object being changed: TEACHER is the existing table, so the statement must begin with ALTER TABLE TEACHER.

2. Describe the structural change: ADD COLUMN introduces FEES, and FLOAT supplies its data type.

3. Combining the clauses gives ALTER TABLE TEACHER ADD COLUMN FEES FLOAT;

Cross-check and contrast

• ADD COLUMN FEES FLOAT INTO TEACHER lacks the required ALTER TABLE clause and uses INTO in a position that does not form an add-column statement.

• UPDATE TEACHER ADD COLUMN FEES FLOAT; starts with UPDATE, whose role is to change values in existing rows.

• INSERT INTO TEACHER ADD COLUMN FEES FLOAT; starts with INSERT INTO, whose role is to insert rows.

Therefore, the command that adds the column is ALTER TABLE TEACHER ADD COLUMN FEES FLOAT;.