Q&A Hero

Q: Which query will output the table contents when the value of the character field P_CODE is alphabetically less than 1558-QW1? a. SELECT P_CODE, P_DESCRIPT, P_QOH, P_MIN, P_PRICE FROM PRODUCT WHERE P_CODE <'1558-QW1'; b. SELECT P_CODE, P_DESCRIPT, P_QOH, P_MIN, P_PRICE FROM PRODUCT WHERE P_CODE = [1558-QW1] c. SELECT P_CODE, P_DESCRIPT, P_QOH, P_MIN, P_PRICE FROM PRODUCT WHERE P_CODE = (1558-QW1) d. SELECT P_CODE, P_DESCRIPT, P_QOH, P_MIN, P_PRICE FROM PRODUCT WHERE P_CODE = {1558-QW1}

Q: Which query will output the table contents when the value of P_PRICE is less than or equal to 10? a. SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE FROM PRODUCT WHERE P_PRICE <> 10; b. SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE FROM PRODUCT WHERE P_PRICE <= 10; c. SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE FROM PRODUCT WHERE P_PRICE => 10; d. SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE FROM PRODUCT WHERE P_PRICE = 10;

Q: Which query will output the table contents when the value of V_CODE is not equal to 21344? a. SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE FROM PRODUCT WHERE V_CODE <> 21344; b. SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE FROM PRODUCT WHERE V_CODE <= 21344; c. SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE FROM PRODUCT WHERE V_CODE = 21344; d. SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE FROM PRODUCT WHERE V_CODE => 21344;

Q: Which query will output the table contents when the value of V_CODE is equal to 21344? a. SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE FROM PRODUCT WHERE V_CODE <> 21344; b. SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE FROM PRODUCT WHERE V_CODE <= 21344; c. SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE FROM PRODUCT WHERE V_CODE = 21344; d. SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE FROM PRODUCT WHERE V_CODE => 21344;

Q: A(n) ____ is a query that is embedded (or nested) inside another query.a. alias b. operator c. subqueryd. view

Q: The ____ command would be used to delete the table row where the P_CODE is 'BRT-345'. a. DELETE FROM PRODUCT WHERE P_CODE = 'BRT-345'; b. REMOVE FROM PRODUCT WHERE P_CODE = 'BRT-345'; c. ERASE FROM PRODUCT WHERE P_CODE = 'BRT-345'; d. ROLLBACK FROM PRODUCT WHERE P_CODE = 'BRT-345';

Q: Which of the following is used to select partial table contents? a. SELECT <column(s)> FROM <Table name> BY <Conditions>; b. LIST <column(s)> FROM <Table name> BY <Conditions>; c. SELECT <column(s)> FROM <Table name> WHERE <Conditions>; d. LIST<column(s)> FROM <Table name> WHERE <Conditions>;

Q: When you issue the DELETE FROM tablename command without specifying a WHERE condition, ____.a. no rows will be deleted b. the first row will be deleted c. the last row will be deletedd. all rows will be deleted

Q: To delete a row from the PRODUCT table, use the ____ command.a. COMMIT b. DELETE c. ERASEd. KILL

Q: Some RDBMSs, such as Oracle, automatically ____ data changes when issuing data definition commands.a. COMMIT b. ROLLBACK c. UNSAVEd. UPDATE

Q: The ____ command is used to restore the table's contents to their previous values.a. COMMIT; RESTORE; b. COMMIT; BACKUP; c. COMMIT; ROLLBACK;d. ROLLBACK;

Q: An example of a command you would use when making changes to a PRODUCT table is ____. a. CHANGE PRODUCT SET P_INDATE = '18-JAN-2004' WHERE P_CODE = '13-Q2/P2'; b. ROLLBACK PRODUCT SET P_INDATE = '18-JAN-2004' WHERE P_CODE = '13-Q2/P2'; c. EDIT PRODUCT SET P_INDATE = '18-JAN-2004' WHERE P_CODE = '13-Q2/P2'; d. UPDATE PRODUCT SET P_INDATE = '18-JAN-2004' WHERE P_CODE = '13-Q2/P2';

Q: UPDATE tablename*****[WHERE conditionlist];The ____ command replaces the ***** in the syntax of the UPDATE command, shown above.a. SET columnname = expression b. columnname = expression c. expression = columnnamed. LET columnname = expression

Q: The SQL command that modifies an attribute"s values in one or more table"s rows is ____.a. INSERT b. SELECT c. COMMITd. UPDATE

Q: In Oracle, the ____ command is used to change the display for a column, for example, to place a $ in front of a numeric value.a. DISPLAY b. FORMAT c. CHARd. CONVERT

Q: To list all the contents of the PRODUCT table, you would use ____.a. LIST * FROM PRODUCT; b. SELECT * FROM PRODUCT; c. DISPLAY * FROM PRODUCT;d. SELECT ALL FROM PRODUCT;

Q: The SQL command that lets you select attributes from rows in one or more tables is ____.a. INSERT b. SELECT c. COMMITd. UPDATE

Q: The SQL command that lets you permanently save data changes is ____.a. INSERT b. SELECT c. COMMITd. UPDATE

Q: The SQL command that lets you insert rows into a table is ____.a. INSERT b. SELECT c. COMMITd. UPDATE

Q: The SQL character data format(s) is(are) ____.a. CHAR and VARCHAR b. VARCHAR only c. Alphanumericd. CHAR only

Q: The most recent fully approved version of standard SQL prescribed by the ANSI is ____.a. SQL-99 b. SQL-2003 c. SQL-4d. SQL-07

Q: When joining three or more tables, you need to specify a join condition for one pair of tables.

Q: To join tables, simply enumerate the tables in the FROM clause of the SELECT statement. The DBMS will create a Cartesian product of every table in the FROM clause. To get the correct results, you need to select the rows in which the common attribute values do not match.

Q: The COUNT function is designed to tally the number of non-null "values" of an attribute, and is often used in conjunction with the DISTINCT clause.

Q: Some RDBMSs, such as Microsoft Access, automatically make the necessary conversions to eliminate case sensitivity.

Q: Most SQL implementations yield case-insensitive searches.

Q: The conditional LIKE must be used in conjunction with wildcard characters.

Q: ANSI-standard SQL allows the use of special operators in conjunction with the WHERE clause.

Q: SQL allows the use of logical restrictions on its inquiries such as OR, AND, and NOT.

Q: Date procedures are often more software-specific than other SQL procedures.

Q: String comparisons are made from left to right.

Q: Since computers identify all characters by their numeric codes, mathematical operators cannot be used to place restrictions on character-based attributes.

Q: Oracle users can use the Access QBE (query by example) query generator.

Q: You can select partial table contents by naming the desired fields and by placing restrictions on the rows to be included in the output.

Q: Although SQL commands can be grouped together on a single line, complex command sequences are best shown on separate lines, with space between the SQL command and the command's components.

Q: All SQL commands must be issued on a single line.

Q: If you have not yet used the COMMIT command to store the changes permanently in the database, you can restore the database to its previous condition with the ROLLBACK command.

Q: The COMMIT command does not permanently save all changes. In order to do that, you must use SAVE.

Q: Any changes made to the contents of a table are not physically saved on disk until you use the SAVE <table name> command.

Q: To list the contents of a table, you must use the DISPLAY command.

Q: You cannot insert a row containing a null attribute value using SQL.

Q: SQL requires the use of the ADD command to enter data into a table.

Q: The CHECK constraint is used to define a condition for the values that the attribute domain cannot have.

Q: Entity integrity is enforced automatically when the primary key is specified in the CREATE TABLE command sequence.

Q: Only numeric data types can be added and subtracted in SQL.

Q: Data type selection is usually dictated by the nature of the data and by the intended use.

Q: SQL is considered difficult to learn; its command set has a vocabulary of more than 300 words.

Q: The ANSI SQL standards are also accepted by the ISO.

Q: The ANSI prescribes a standard SQL"the current fully approved version is known as SQL-07.

Q: A database language enables the user to perform complex queries designed to transform the raw data into useful information.

Q: A database language enables the user to create database and table structures to perform basic data management chores.

Q: Tables within a database share common attributes that enable the tables to be linked together.

Q: Depending on the sophistication of the application development software, nulls can create problems when functions such as COUNT, AVERAGE, and SUM are used.

Q: There is never a good reason to use null values in a database.

Q: A null is created when you press the Enter key or the Tab key to move to the next entry without making a prior entry of any kind.

Q: If the attribute (B) is functionally dependent on a composite key (A) but not on any subset of that composite key, the attribute (B) is fully functionally dependent on (A).

Q: Only a single attribute, not multiple attributes, can define functional dependence.

Q: In a relational model, if A determines B, C, and D, you write A = B, C, D.

Q: The idea of determination is unique to the database environment.

Q: Each table in a relational database must have a primary key.

Q: Character data can contain any character or symbol intended for mathematical manipulation.

Q: Numeric data are data on which you can perform meaningful arithmetic procedures.

Q: The order of the rows and columns is important to the DBMS.

Q: Because the relational model uses attribute values to establish relationships among tables, many database users correctly assume that the term relation refers to such relationships.

Q: You can think of a table as a persistent representation of a logical relation.

Q: The practical significance of taking the logical view of a database is that it serves as a reminder of the simple file concept of data storage.

Q: What is the system catalog?

Q: Describe the use of the UNION operator.

Q: Describe the use of nulls in a database.

Q: What is a key and why is it important in the relational model?

Q: What are the characteristics of a relational table?

Q: Codd's rule of ____________________ states that every value in a table is guaranteed to be accessible through a combination of table name, primary key value, and column name.

Q: The index key can have multiple attributes, this is called a(n) ____________________ index.

Q: A(n) ____________________ index is an index in which the index key can have only one pointer value (row) associated with it.

Q: A(n) ____________________is an orderly arrangement used to logically access rows in a table.

Q: Proper data ____________________ design requires carefully defined and controlled data redundancies to function properly.

Q: The proper use of ____________________ keys is crucial to controlling data redundancy.

Q: Fortunately, the problems inherent in the ____________________ relationship can easily be avoided by creating a composite entity.

Q: ____________________ relationships can be implemented by creating a new entity in 1:M relationships with the original entities.

Q: If one department chaira professorcan chair only one department and one department can have only one department chair, then the entities PROFESSOR and DEPARTMENT exhibit a(n) ____________________ relationship.