Which rule state that 'no component of a primary key can accept a NULL value'? MCQ with Answer and Explanation

Explanation:
A Cursor is a database control structure that allows an application or script to traverse over the records of a query result set row by row.

Explanation:
In SQL pattern matching with the LIKE operator, the underscore (*) represents exactly one single character, while the percent sign (%) matches zero or more characters.

Explanation:
Both syntaxes are valid: explicit JOIN syntax and implicit comma join with WHERE conditions.