What are the conditions where a foreign key must not be null.

Q: Does the DBMS or the user make the choice of which index to use to accomplish a given task?

A: Solution:-              The DBMS, net the user, choose which  index   to use to accomplish a…

Q: How do you pronounce enhanced key? What does enhanced key mean?

A: An improved keyboard is a kind of keyboard that comes standard with virtually all modern PCs. It…

Q: The trigger below is defined on the relation T (C, D) with the primary key on the attr

A:

Q: What are rhe types of subquery?

A: INTRODUCTION: A subquery is a query that is contained within a larger query statement. Subqueries…

Q: What is Composite Key?

A: A Composite key is a DBMS key with two or more attributes that combine to identify the Tuple in the…

Q: How is a foreign key different from a primary key?

A: Primary key is an attribute of a relation which is used to uniquely identity each tuple of the…

Q: Give an example of the word "foreign key

A: Please find the answer below :

Q: Explain how primary keys and foreign keys are denoted in this book

A: Primary Key:-   The PRIMARY KEY constraint uniquely identifies each record in a table. Primary keys…

Q: Each key that meets the criteria for a primary key is called functional key a O lookup key b O…

A: According to the asked question, the solution is given below with a proper explanation.

Q: What is the definition of the Candidate key?

A: Candidate key: A row in a relational database is identified by one or more columns (fields) that are…

Q: Under what conditions must a foreign key not be null?

A: Answer: So basically a foreign key is used for identifying a row of another table uniquely.…

Q: Describe how a foreign key is different from a primary key

A: Difference between foreign and primary key:

Q: What subquery kinds are there?

A: The solution to the given problem is below.

Q: Explain references the primary key in the same relation?

A: The primary key constraint is that each row in the relational database management system table is…

Q: Can a foreign key have duplicate values?

A: Foreign key: Foreign key in one table that points to primary key in another table. Can a foreign key…

Q: What are the references to the main key in the same relation?

A: Introduction: The primary key constraint requires that each row in the relational database…

Q: Employee EMPNO NUMBER(4) - Primary Key VARCHAR2(10)- Not Null VARCHAR2(9) DATE NUMBER(7,2) NUMBER(2)…

A: The Answer is in below step...

Q: What exactly is a foreign key?

A: Intro Foreign keys are columns or groups of columns in a relational database table that serve as a…

Q: What is the meaning of the primary key?

A: A primary key, sometimes known as the main keyword, is a unique identifier for each entry in a…

Q: What is a unique key?

A: What is a unique key?

Q: Write a detailed contrast between "Primary key" & "Composite key" in Dbms

A: Primary Key is that column of a table whose each row data is uniquely identified. It can never be…

Q: Assume a user establishes a new relation r1 that has a foreign key that points to another relation…

A: Foreign key: It is a collection of attributes in a table that relates to another table's primary…

Q: In SQL, the data in a relation can be retrieved/displayed in ascending/descending order using…

A: According to the question we generally use sql commands for retrieve the data from database and for…

Q: How many times has each book title been borrowed? Give the new column an alias.

A: Hey there, I am writing the required solution based on the above given question. Please do find the…

Q: explain the function of the FOREIGN KEY definition.

A: Functions of Foreign Key: It ensures that data is integral It is a constraint that prevents actions…

Q: Why can a foreign key have a NULL value but a primary key cannot?

A: INTRODUCTION: The term "foreign key" refers to a database key that connects two tables. The…

Q: What is a primary key?

A: Primary key: Primary key refers to an attribute which is used to uniquely recognize each tuple in…

Q: Create both correlated and noncorrelated subqueries and know when to employ them.

A: The answer is

Q: Let's say a user establishes a new relation r1 that has a foreign key that points to another…

A: Introduction: A foreign key (FK) is like a column or collection of columns that is used to create…

Q: Explain the key terms Super Keys, Candidate keys and Primary Key.

A: Ans : Super Key: it is a group of single or multiple keys which is used to identifies rows in the…

Q: What is correlated subqueries?

A: Answer: Corelated subquery:- Before going to corelated subquery i just want to let you know about…

Q: Would you be able to tell the difference between a composite main key and one that has a candidate…

A: Key: A key is an attribute or combination of characteristics that enable us to identify a tuple in a…

Q: What is alternate, artificial, compound and natural key?

A: Alternate key: Alternate keys are just candidate keys except the primary keys. Artificial key:…

Q: According to the figure, the primary key is :

A: The correct answer is ProjectID. Explanation is provided in the 2nd step

Q: what is Foreign key ?

A: A FOREIGN KEY is a field or collection of fields in a table that refers to the primary key in…

Q: Explain Primary Key?

A: Definition: A primary key is a special column (or combination of columns)of the relational database…

Q: 18. What happens if you update an instructor's salary to 20000? Why did it happen so? The integrity…

A: If we try to update instructor salary to 20000. It will give error and data will not be updated.…

Q: A foreign key should normally have the same name as the primary key from which it was copied. Group…

A: It is a RDBMS based question.

Q: Distinguish between the phrases main key, candidate key, and superkey and explain why they are used…

A: Key A key is an attribute or set of attributes which helps us in uniquely identifying the rows of a…

Q: Explain the difference between Primary Key and Foreign Key , give example

A: We are going to understand difference between Primary Key and Foreign Key along with examples.

Q: What is the difference between a main key and a candidate key?

A: Foundation: Candidate keys are selected to uniquely identify tuples in a database, and the primary…

Q: Could you please explain about foreign key with an example?

A: Given To know about the foreign key

Q: Write a Stored Procedure for the below given relation to validate the user credentials (User 1 and…

A: A stored procedure has to be created to validate the user credentials which has to accept the user…

Procedures in SQL

A pre-compiled stored procedure is a logical unit made up of one/more SQL statements (SQL stands for Structured Query Language). The database server saves it as an object. An SQL procedure is a collection of SQL statements and logic that is written and saved to accomplish a specified goal. An SQL procedure consists of a name, a parameter list, and a set of Transact-SQL statements. Stored procedures are stored as named objects in SQL Database Server.