Which command would NOT be used in SQL arithmetic expressions?

• A. Add
• B. Multiply
• C. Concatenate
• D. Subtract

Answer: (C)

In SQL arithmetic expressions, the operations typically involve mathematical calculations such as addition, subtraction, multiplication, and division. Therefore, the command that would not be used in arithmetic expressions is the one related to concatenation.

Concatenation is the process of joining two or more strings together, which falls under string manipulation rather than arithmetic. In SQL, concatenation is often performed using the || operator or the CONCAT function, depending on the SQL dialect being used. Thus, while commands for addition, multiplication, and subtraction directly relate to numeric computations, the concatenate command serves a different purpose entirely, making it irrelevant in the context of arithmetic expressions.