Exam 98-364 topic 1 question 137 discussion

Actual exam question from Microsoft's 98-364

Question #: 137
Topic #: 1

This question requires that you evaluate the underlined text to determine if it is correct.
A relational database management system employs the concept of an attribute to ensure that data entered into a field in a column is valid.
Instructions: Review the underlined text. If it makes the statement correct, select "No change is needed." If the statement is incorrect, select the answer choice that makes the statement correct.

A. No change is needed
B. a primary key
C. a constraint
D. an index

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Suggested Answer: C 🗳️

by drx at Aug. 24, 2020, 3:57 p.m.

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drx

Highly Voted 4 years, 9 months ago

"SQL constraints are used to specify rules for the data in a table. Constraints are used to limit the type of data that can go into a table. This ensures the accuracy and reliability of the data in the table. If there is any violation between the constraint and the data action, the action is aborted. Constraints can be column level or table level. Column level constraints apply to a column, and table level constraints apply to the whole table. The following constraints are commonly used in SQL: NOT NULL - Ensures that a column cannot have a NULL value UNIQUE - Ensures that all values in a column are different PRIMARY KEY - A combination of a NOT NULL and UNIQUE. Uniquely identifies each row in a table FOREIGN KEY - Uniquely identifies a row/record in another table CHECK - Ensures that all values in a column satisfies a specific condition DEFAULT - Sets a default value for a column when no value is specified INDEX - Used to create and retrieve data from the database very quickly"

upvoted 13 times

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