3rd Edition

ISBN: 9781305251038

Author: Joan Casteel

Publisher: Cengage Learning

Concept explainers

SQL stands for Structured Query Language, is a form of communication that uses queries structured in a specific format to store, manage & retrieve data from a relational database.

Queries

A query is a type of computer programming language that is used to retrieve data from a database. Databases are useful in a variety of ways. They enable the retrieval of records or parts of records, as well as the performance of various calculations prio…

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Textbook Question

Chapter 4, Problem 20MC

Which of the following is the valid syntax for adding a PRIMARY KEY constraint to an existing table?

a. ALTER TABLE tablename ADD CONSTRAINT PRIMARY KEY (columnname);
b. ALTER TABLE tablename ADD CONSTRAINT (columnname) PRIMARY KEY constraintname;
c. ALTER TABLE tablename ADD [CONSTRAINT constraintname] PRIMARY KEY;
d. None of the above is valid syntax.

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Chapter 4, Problem 19MC

Chapter 4, Problem 1HOA

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Chapter 4 Solutions

Oracle 12c: SQL

Ch. 4 - What is the difference between a PRIMARY KEY...Ch. 4 - How can you verify the constraints that exist for...Ch. 4 - A table can have a maximum of how many PRIMARY KEY...Ch. 4 - Which type of constraint can be used to make...Ch. 4 - Which type of constraint should you use to ensure...Ch. 4 - How is adding a NOT NULL constraint to an existing...Ch. 4 - When must you define constraints at the table...Ch. 4 - Prob. 8RQ Ch. 4 - What is the difference between disabling a...Ch. 4 - Prob. 10RQ

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Solution Summary: The author explains that none of the given commands are valid SQL syntax for adding a PRIMARY KEY constraint to an existing table.

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Chapter 4 Solutions