Which command is used to retrieve data from a database? MCQ with Answer and Explanation

Explanation:
A Transaction is a sequence of one or more SQL operations treated as a single, indivisible unit of work that must either succeed completely or fail completely.

Explanation:
Out of all available candidate keys, the one selected to identify rows uniquely is the primary key, and the remaining unselected candidate keys are called alternate keys.

Explanation:
A self join is a join where a table is joined with itself, often used to compare rows within the same table.