10 Questions
What is the purpose of the CHECK constraint in the student table?
The CHECK constraint in the student table ensures that the age of a student is greater than 18.
What error message is displayed when trying to insert a student with an age less than 18?
The error message displayed is CHECK constraint failed: age>18.
How are the entities in the ER model mapped to tables in the relational database?
Each entity in the ER model becomes a table, and all attributes of the entity become columns of the table. The key attribute of the entity becomes the primary key of the table.
How are relationships in the ER model mapped to tables in the relational database?
Each relationship in the ER model becomes a table, and the key attributes of the participating entities in the relationship become the columns of the table. If the relationship has any attributes, they also become columns of the table.
What is the purpose of the PRIMARY KEY constraint in the Employee and Department tables?
The PRIMARY KEY constraint ensures that the EmpID column in the Employee table and the DeptID column in the Department table uniquely identify each row in the respective tables.
What is the purpose of the INSERT INTO statement in the example?
The INSERT INTO statement is used to add new rows of data to the student table.
What is the purpose of the SELECT * FROM statement in the example?
The SELECT * FROM statement is used to retrieve all the rows and columns from the student table.
What is the purpose of the CHECK constraint in the student table?
The CHECK constraint in the student table ensures that the age of a student is greater than 18.
What is the purpose of the DBMS UNIT II LOGICAL DATABASE DESIGN section in the text?
The DBMS UNIT II LOGICAL DATABASE DESIGN section explains the process of mapping entities and relationships from the ER model to tables in the relational database.
What is the purpose of the CREATE TABLE statements in the example?
The CREATE TABLE statements are used to define the structure of the Employee and Department tables, including the columns and their data types, as well as the primary key constraints.
Learn about relation schema in DBMS, including the representation of relations with attributes. Explore concepts such as degree, cardinality, and NULL values in database tables. Understand the properties of relations and their unique characteristics.
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