Question

The CUSTOMERS table has these columns: CUSTOMER_ID NUMBER(4) NOT NULL CUSTOMER_NAME VARCHAR2(100) NOT NULL CUSTOMER_ADDRESS VARCHAR2(150) CUSTOMER_PHONE VARCHAR2(20) You need to produce output that states "Dear Customer customer_name, ". The customer_name data values come from the CUSTOMER_NAME column in the CUSTOMERS table. Which statement produces this output?

Answer 1

Answer:

SELECT "Dear Customer", CUSTOMER_NAME
FROM CUSTOMERS;

Explanation:

Including text as an argument in SELECT: the text will appear in the query output.

Answer 2

Answer:

SELECT ‘Dear Customer ‘ ||  CUSTOMER_NAME || ‘,’ FROM CUSTOMERS;

Explanation:

• A Select statement is used to retrieve information from a database.
• A select statement is formed of the three clauses SELECT, FROM and WHERE and has the following form:

        SELECT <attribute list>

        from <table list>

        where <condition>

• <attribute list> : is a list of attribute name whose values are to be retrieved by the query.

• <table list> : is a list of the relation names required to process the query.
• <condition> : is a conditional expression that identifies the tuple to be retrieved by the query.
• A Concatenation operator is used to create a resultant column that is a character expression.
• Here, in the above select query (SELECT ‘Dear Customer ‘ ||  CUSTOMER_NAME || ‘,’ FROM CUSTOMERS;) , we have used || which is known as Concatenation operator which is used to add two or as many columns as we want in our select query and it is independent of the datatype of column.