Question

12 multiple answer 4 points select all the data integrity principles of dbms. all columns must contain values data can be entered without any validation checks arrays or repeated data groups are not allowed as column values null values are used when no data is present duplicate rows are not permitted previous

Explanation:

• All columns must contain values: Incorrect. DBMS allows null values (missing or unknown data) in columns.
• Data can be entered without any validation checks: Incorrect. Data validation is a key part of DBMS to ensure data integrity (e.g., type, range checks).
• Arrays or repeated data groups are not allowed as column values: Correct. Most DBMS (like relational DBs) follow the first normal form (1NF), which prohibits multi - valued attributes (arrays or repeated groups in a single column).
• Null values are used when no data is present: Correct. Null is a special marker in DBMS to represent the absence of data or unknown value.
• Duplicate rows are not permitted: Correct. In a relation (table) in DBMS, each row should be unique (based on primary key or overall row content for data integrity), so duplicate rows are not allowed.

Answer:

C. Arrays or repeated data groups are not allowed as column values
D. Null values are used when no data is present
E. Duplicate rows are not permitted