DB SQL Exam Practice Questions and Answers

DB SQL Exam Practice Questions and Answers The ________ is the structure that contains descriptions of objects such as tables and views created by users. - ANSWER-schema ________ is a set of commands used to control a database, including security. - ANSWER-DCL ________ is a set of commands used to update and query a database. - ANSWER-DML DDL is typically used during which phase of the development process? - ANSWER-Physical design The main concept of relational databases was published in 1970 by: - ANSWER-E.F.Codd. Relational databases are heavily based on the mathematical concept of: - ANSWER-Set Theory. The command for creating a database is: - ANSWER-create schema. The SQL command ________ defines a logical table from one or more tables or views. - ANSWER- create view Any create command may be reversed by using a(n) ________ command. - ANSWER-drop The first in a series of steps to follow when creating a table is to: - ANSWER-identify each attribute and its characteristics. The SQL command ________ adds one or more new columns to a table. - ANSWER-alter table INSERT INTO is an example of ________ code. - ANSWER-DML Copyright © KAYLIN 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH NOVEMBER, 2024 Copyright ©Stuvia International BV Page 2/14 What does the following SQL command do? insert into Customer_T values (001,'John Smith','231 West St','Boston','MA','02115') - ANSWER-Adds a new record to the Customer_T Given a table named store with 5 fields: store_id, address, city, state, zipcode, why would the following insert command not work? insert into store values ('234 Park Street') - ANSWER-You must specify the fields to insert if you are only inserting some of the fields. Which of the following is a technique for optimizing the internal performance of the relational data model? - ANSWER-Clustering data Indexes are created in most RDBMSs to: - ANSWER-provide rapid random and sequential access to base-table data. In an SQL statement, which of the following parts states the conditions for row selection? - ANSWER- Where The first part of an SQL query to be read is the ________ statement. - ANSWER-FROM The last part of an SQL query to be read is the ________ statement. - ANSWER-ORDER BY - ANSWER- What does the following SQL statement do? Select * From Customer Where Cust_Type = "Best" - ANSWER-Selects all the fields from the Customer table for each row with a customer labeled "Best" What result will the following SQL statement produce? Select Avg(standard_price) as average from Product_V - ANSWER-The average Standard_Price of all products in Product_V Which of the following questions is answered by the SQL statement? Select Count (Product_Description) from Product_T - ANSWER-How many products have product descriptions in the Product Table? Copyright © KAYLIN 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH NOVEMBER, 2024 Copyright ©Stuvia International BV Page 3/14 Which of the following counts ONLY rows that contain a value? - ANSWER-Count Which of the following will produce the minimum of all standard prices? - ANSWER-Select min(standard_price) from Product_V; Which of the following is the wildcard operator in SQL statements? - ANSWER-* To eliminate duplicate rows in a query, the ________ qualifier is used in the SQL Select command. - ANSWER-distinct To get all the customers from Hawaii sorted together, which of the following would be used? - ANSWER-ORDER BY A single value returned from an SQL query that includes an aggregate function is called a(n): - ANSWER-scalar aggregate. Multiple values returned from an SQL query that includes an aggregate function are called: - ANSWER-vector aggregates. Which of the following can produce scalar and vector aggregates? - ANSWER-GROUP BY Which of the following finds all groups meeting stated conditions? - ANSWER-Having Which of the following is true of the order in which SQL statements are evaluated? - ANSWER-The SELECT clause is processed before the ORDER BY clause. A ________ view is materialized when referenced. - ANSWER-dynamic A view may not be updated directly if it contains: - ANSWER-the HAVING clause. Copyright © KAYLIN 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH NOVEMBER, 2024 Copyright ©Stuvia International BV Page 4/14 4Requiring a CustomerID to exist in a Primary table before it can exist in a foreign table is an example of: - ANSWER-Referential Integrity. Referential Integrity Constraints are generally established between: - ANSWER-Primary and Foreign keys. Which of the following is a purpose of the SQL standard? - ANSWER-To specify syntax and semantics of SQL data definition and manipulation The benefits of a standardized relational language include: - ANSWER-cross-system communication. A catalog is the structure that contains object descriptions created by a user. - ANSWER-FALSE DCL is used to update the database with new records. - ANSWER-FALSE A database table is defined using the data definition language (DDL). - ANSWER-TRUE A database is maintained and queried using the data mapping language (DML). - ANSWER-FALSE