Question 1

The LIKE operator in the SQL SELECT command WHERE clause allows the use of wildcards to substitute for character strings.

Accepted Answer

The LIKE operator in the SQL SELECT command WHERE clause does allow the use of wildcards to substitute for character strings.

Question 2

If several AND and OR operators appear in an SQL SELECT command WHERE clause and they are not separated by parentheses, all of the OR operations will be performed before any of the AND operations.

Accepted Answer

In SQL, the AND operator has higher precedence than the OR operator, so AND operations are performed before OR operations if they are not explicitly grouped with parentheses.

Question 3

The DISTINCT operator in the SQL SELECT command removes duplicate rows from a query result.

Accepted Answer

The DISTINCT operator is used in SELECT statements to remove duplicates from the result set. Therefore, the statement is true.

Question 4

The tables used in a SELECT command are listed in the FROM clause.

Accepted Answer

The FROM clause of a SELECT command is where the tables being queried are listed.

Question 5

The OR operator in the SQL SELECT command WHERE clause means one or the other, but not both.

Accepted Answer

The OR operator in SQL returns true when either of the conditions being compared is true, including when both conditions are true.

Question 6

The ORDER BY operator in the SQL SELECT command orders a query result's output rows by a set of attribute values.

Accepted Answer

The ORDER BY operator is used to sort the result set by one or more columns.

Question 7

The BETWEEN operator in the SQL SELECT command WHERE clause requires that a character string must be between two specified character strings.

Accepted Answer

The BETWEEN operator in the SQL SELECT command WHERE clause requires that a value must be between two specified values, but it doesn't necessarily need to be a character string. It can also be used with numeric values, dates, and times.

Question 8

The HAVING clause limits the results of a GROUP BY clause based on the values calculated for each group with the built-in functions.

Accepted Answer

The HAVING clause is used to filter the results of a GROUP BY query based on the results of aggregate functions applied to the grouped values. It is used in conjunction with the GROUP BY clause.

Question 9

Only two tables can be joined in an SQL SELECT statement.

Accepted Answer

Multiple tables can be joined in an SQL SELECT statement using JOIN statements.

Question 10

A basic SQL SELECT command is capable of performing a combination of relational Select and Project operations.

Accepted Answer

The SELECT command in SQL can be used to select specific columns or fields from one or more tables, as well as filter records based on certain conditions. This is equivalent to a combination of relational Select and Project operations.

Question 11

To retrieve an entire table, an SQL SELECT statement must specify the rows in the WHERE clause.

Accepted Answer

To retrieve an entire table, you can simply use the SQL SELECT statement without specifying any conditions in the WHERE clause.

Question 12

The only way to retrieve all of the fields of a table with an SQL SELECT command is to list them all in the SELECT clause.

Accepted Answer

You can use the asterisk (*) symbol in the SELECT clause to retrieve all fields from a table without listing them individually.

Question 13

In the SQL SELECT command embedded mode, the user types the command at a workstation and presses the Enter key. The command goes directly to the relational DBMS, which evaluates the query and processes it against the database.

Accepted Answer

In embedded SQL, SQL commands are embedded within the code of a host language (like C, C++, or Java) and are not directly typed at a workstation and sent to the DBMS. Instead, they are preprocessed by an embedded SQL preprocessor before the host program is compiled, linking SQL commands with the host language's syntax.

Question 14

A basic SQL SELECT command is capable of retrieving a single column value from a single row of a table.

Accepted Answer

A basic SQL SELECT command can retrieve multiple columns and multiple rows from a table, but it can also retrieve a single column value from a single row through the use of WHERE clause.

Question 15

Search arguments appear in the SQL SELECT command WHERE clause.

Accepted Answer

The SQL SELECT command allows for filtering of results through the WHERE clause, which contains search arguments that specify the conditions that must be met in order for a row to be returned in the query result set.

Question 16

The built-in function COUNT in an SQL SELECT command adds a specified set of attribute values.

Accepted Answer

The COUNT function in SQL is used to count the number of rows in a result set, not to add attribute values.

Question 17

A GROUP BY clause in an SQL SELECT command groups together columns based on common attribute values.

Accepted Answer

The answer of A GROUP BY clause in an SQL...

Question 18

All of the standard comparison operators can be use in the SQL SELECT command WHERE clause.

Accepted Answer

This statement is true. The SQL SELECT command WHERE clause allows the use of standard comparison operators such as equals (=), not equals (<>), greater than (>), less than (<), greater than or equal to (>=), and less than or equal to (<=).

Question 19

SQL SELECT commands must be issued against the actual, physical database tables rather than against "logical views" of the tables.

Accepted Answer

SQL SELECT commands can be issued against both actual, physical database tables and against "logical views" of the tables. Views are virtual tables that represent data in a format convenient for analysis, without altering the underlying physical tables.

Question 20

Once a GROUP BY clause in an SQL SELECT command groups together rows based on common attribute values, a built-in function can produce a result for each group.

Accepted Answer

Once a GROUP BY clause is used, a built-in function can produce a result for each group.

Quiz 4: Relational Data Retrieval: SQL