The difference between a primary key and a unique key is a Both Primary and

The difference between a primary key and a unique key

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Question 7The difference between a primary key and a unique key is a. Both Primary and Unique Key is implemented for Uniqueness of the column. Primary Key creates a unclustered index of column and Unique creates an unclustered index of column. Moreover, Primary Key doesn’t allow NULL value, however Unique Key does allow one NULL value.Selected:b. Both Primary and Unique Key is implemented for Uniqueness of the column. Primary Key creates a clustered index of column where as an Unique creates unclustered index of column. Moreover, Primary Key doesn’t allow NULL value, however Unique Key does allows one NULL value.This answer is correct.c. Both Primary and Unique Key is implemented for Uniqueness of the column. Primary Key creates a clustered index of column and Unique creates clustered index of column. Moreover, Primary Key doesn’t allow NULL value, however Unique Key does allow one NULL value.d. Both Primary and Unique Key is implemented for Uniqueness of the column. Primary Key creates a clustered index of column where as an Unique creates unclustered index of column. Moreover, Primary Key allows one NULL value just like a Unique Key.Correct!Choice a) is incorrect because a primary key is a clustered index.Choice c) is incorrect because a unique key is a nonclustered index.Choice d) is incorrect because a primary key does not all a null value. 1 /1 Question 8When table fuinfo is initially loaded with 10 million records, the email addresses were not included. Youwere recently supplied those email addresses and now you need to update those records. What should you do before updating those records?Questions 12 - 14 are based on the following table definition:CREATE TABLE fuinfo(fid int(10) unsigned NOT NULL,name varchar(40) NOT NULL,email varchar(128) NOT NULL,UNIQUE KEY email (email),UNIQUE KEY fid (fid)) ENGINE=MyISAM DEFAULT CHARSET=utf8
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