​ Structure of the ORDERS Table

question 32

Multiple Choice

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Structure of the ORDERS table
Structure of the CUSTOMERS table
​
-​Which of the following SQL statements will list the name of each customer stored in the CUSTOMERS table,and,if the customer has placed an order that is contained in the ORDERS table,the order# of any order each customer has placed?

• A) SELECT lastname,firstname,order# FROM customers NATURAL JOIN orders WHERE orders.customer# IS NOT NULL;
• B) SELECT lastname,firstname,order# FROM customers,orders WHERE orders.customer# (+)= customers.customer#;
• C) SELECT lastname,firstname,order# FROM customers,orders WHERE orders.customer# = customers.customer# (+);
• D) SELECT lastname,firstname,order# FROM customers NATURAL JOIN orders WHERE orders.customer# IS NULL;

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Definitions:

Sample Mean

The average of all observations or data points in a sample, used as an estimate of the population mean.

Population Standard Deviation

A measure of the dispersion or spread of a population's values around its mean, quantifying variability.

P-value Method

A statistical approach used to determine the significance of results in hypothesis testing, indicating the probability of observing data as extreme as the sample data.

Null Hypothesis

It is a hypothesis that assumes no significant difference or effect; it is the statement tested in statistical hypothesis testing to determine the likelihood of the observed data.