Which of the following are true about primary keys? SELECT ALL THAT APPLY. A) They must reference one or more columns in a single table. B) They are usually implemented using an index. C) They guarantee that no two rows in a table have duplicate primary key values. D) They must be defined for every database table.

Which of the following are true about primary keys? SELECT ALL THAT APPLY. A) They must reference one or more columns in a single table. B) They are usually implemented using an index. C) They guarantee that no two rows in a table have duplicate primary key values. D) They must be defined for every database table.

A Guide to SQL

9th Edition

ISBN:9781111527273

Author:Philip J. Pratt

Publisher:Philip J. Pratt

Chapter2: Database Design Fundamentals

Section: Chapter Questions

Problem 11RQ

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8. Matrix algebra is a theoretical way of manipulating a database. 9. The union of tables A and B is a table containing all rows that are in either table A or table B or in both table A and table B. 10. The intersection of two tables A and B is the set of all rows that are in table A but that are not in table B.
Answer the following prompts 1The InstantRide Management team founded a new team for car maintenance. The new team is responsible for the small maintenance operations for the cars in the InstantRide system. The main idea is to take actions faster and minimize the time spent for the maintenance. Therefore, the Car Maintenance team wants to store MAINTENANCE_TYPE_ID (char(5)) and a MAINTENANCE_TYPE_DESCRIPTION (varchar(30)) in the database. Using MAINTENANCE_TYPE_ID as the PRIMARY KEY, create a new table, MAINTENANCE_TYPES, and send the table description with the column names and types to the Car Maintenance team. 2The Car Maintenance team also wants to store the actual maintenance operations in the database. The team wants to start with a table to store CAR_ID (CHAR(5)), MAINTENANCE_TYPE_ID (CHAR(5)) and MAINTENANCE_DUE (DATE) date for the operation. Create a new table named MAINTENANCES. The PRIMARY_KEY should be the combination of the three fields. The CAR_ID and MAINTENANCE_TYPE_ID…
Describe the concept of "lazy loading" in the context of database connectivity.
Task 1: The InstantRide Management team founded a new team for car maintenance. The new team is responsible for the small maintenance operations for the cars in the InstantRide system. The main idea is to take actions faster and minimize the time spent for the maintenance. Therefore, the Car Maintenance team wants to store MAINTENACE_TYPE_ID (char(5)) and a MAINTENANCE_TYPE_DESCRIPTION (varchar(30)) in the database. Using MAINTENANCE_TYPE_ID as the PRIMARY KEY, create a new table, MAINTENANCE_TYPES, and send the table description with the column names and types to the Car Maintenance team. Task 2: The Car Maintenance team also wants to store the actual maintenance operations in the database. The team wants to start with a table to store CAR_ID (CHAR(5)), MAINTENANCE_TYPE_ID (CHAR(5)) and MAINTENANCE_DUE (DATE) date for the operation. Create a new table named MAINTENANCES. The PRIMARY_KEY should be the combination of the three fields. The CAR_ID and MAINTENACNE_TYPE_ID should be foreign…
Task 1: The InstantRide Management team founded a new team for car maintenance. The new team is responsible for the small maintenance operations for the cars in the InstantRide system. The main idea is to take actions faster and minimize the time spent for the maintenance. Therefore, the Car Maintenance team wants to store MAINTENACE_TYPE_ID (char(5)) and a MAINTENANCE_TYPE_DESCRIPTION (varchar(30)) in the database. Using MAINTENANCE_TYPE_ID as the PRIMARY KEY, create a new table, MAINTENANCE_TYPES, and send the table description with the column names and types to the Car Maintenance team.
Task 1:The InstantRide Management team founded a new team for car maintenance. The new team is responsible for the small maintenance operations for the cars in the InstantRide system. The main idea is to take actions faster and minimize the time spent for the maintenance. Therefore, the Car Maintenance team wants to store MAINTENACE_TYPE_ID (char(5)) and a MAINTENANCE_TYPE_DESCRIPTION (varchar(30)) in the database. Using MAINTENANCE_TYPE_ID as the PRIMARY KEY, create a new table, MAINTENANCE_TYPES, and send the table description with the column names and types to the Car Maintenance team. THIS IS FOR CENGAGE MYSQL
The execution of a trigger can cause another action to be triggered. Most database systems place a limit on how deep the nesting can be. Explain why they might place such a limit.
branch(branchhame, branch+citysassets} customer (HD, Customer name, customer street, customer city) loan loan number branch_name, amounty borrower(ID; loan_number account (account_number, branch name, balance)e depositor (HDs account number)- Figure le Consider the bank database in Figure 1, where the primary keys are underlined. Each branch might have many loans or accounts, associated with borrowers or depositors, respectively. Construct the following SQL queries for this relational database. 1. Find the name of each branch that has at least one customer who has an account in the bank and who lives in the "Harrison" city. Make sure each branch name only appears once. 2. Find the ID of each customer who lives on the same street and in the same city as customer "12345". (1) Please use "tuple variables". e (2) Please use "derived relations" or “with". 3. Find the ID of each customer of the bank who has an account but not a loan. 4. Find the total sum of all loan amounts for each branch…
A database at a college must support the following requirements: a. For a department, store its number and name. b. For an advisor, store his or her number, last name, first name, and the department number to which the advisor is assigned. c. For a course, store its code and description (for example, DBA210, SQL Programming). d. For a student, store his or her number, first name, and last name. For each course the student takes, store the course code, course description, and grade earned. Also, store the number and name of the student's advisor. Assume that an advisor might advise any number of students but that each student has just one advisor. Design the database for the preceding set of requirements. Determine any functional dependencies. List the tables, columns, and relationships. In addition, represent your design with an E-R diagram.
To access a database, we need to open a connection to it first and close it once our job is done. Connecting to a database depends on the type of the target database and the database management system (DBMS). For example, connecting to a SQL Server database is different from connecting to an Oracle database. But both these connections have a few things in common: •They have a connection string •They can be opened•They can be closed•They may have a timeout attribute (so if the connection could not be opened within the timeout, an exception will be thrown).Your job is to represent these commonalities in a base class called DbConnection. This class should have two properties: ConnectionString : stringTimeout : TimeSpanA DbConnection will not be in a valid state if it doesn’t have a connection string. So you need to pass a connection string in the constructor of this class. Also, take into account the scenarios where null or an empty string is sent as the connection string. Make sure to…
Database Schema: branch ( branch_name, branch_city, assets ) customer ( ID, customer_name, customer_street, customer_city ) loan ( loan_number, branch_name, amount ) borrower ( ID, loan_number ) account ( account_number, branch_name, balance ) depositor ( ID, account_number ) Write a (postgresql) "trigger function" and "create a trigger" to carry out the following action: On delete of an account, for each customer-owner of the account, check if the owner has any remaining accounts, and if she does not, delete her from the depositor relation.
7. A “natural join" in a relational database takes two tables of information and combines entries from the tables that share a particular field. You can read more about this at Wikipedia. Interpret the tables below as sets of sets? For the Course Enrollment Table define A = {{A38182818, Spring2021, Math230, 01}, ..., {A56363631, Spring2021, Math454, 01}}, and for the Student Table define B = {{Al, A81723653}, {Jo, A38182818}, {Su, A56363631}}. Course Enrollment Table Student Table A38182818 | Spring2021 | Math230 | 01 A81723653 | Spring2021 | Math350 01 Al A81723653 A81723653 Fall2020 Math152 04 Jo A56363631 A38182818 Fall2020 Math332 02 Su A38182818 A56363631 | Spring2021 Math454 | 01 (a) Construct the set C = {xUy : x € A, y E B, x N y # 0}. (b) Represent the resulting set C from part (a) as a table, similar to what you see above. Make sure to write down the table for C in a reasonably sorted order. (c) Why would you want to query the database for the set {x € C : Al e x}? Be…

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