Oracle Updated 1z0-071 Exam Questions and Answers by stephen

The behavior of data insertion into a table with a specific numeric format in Oracle Database 12c can be explained as follows:

A. INSERT INTO rate_list VALUES (-.9) inserts the value as -.9: This is correct. The value -.9 is within the precision defined by the table column (NUMBER(6,2)), where 6 is the total number of digits (including both sides of the decimal point), and 2 is the number of digits after the decimal point.

E. INSERT INTO rate_list VALUES (0.551) inserts the value as .55: Oracle rounds the number to the nearest value that fits the specified scale of 2. Thus, 0.551 rounds down to 0.55.

References:

Oracle Database SQL Language Reference 12c, particularly sections on data types and numeric precision.

When evaluating whether expressions in SQL queries are valid, consider data type compatibility and the operations performed:

Option A: Valid. The expression performs arithmetic operations (multiplication and division) on numeric data types (unit_price, constants). These operations are allowed and make sense in a mathematical context.

Option B: Valid. This query calculates the difference between two dates (expiry_date and delivery_date), which results in a numeric value representing the number of days between the dates. The result is then multiplied by 2, which is a valid operation on a numeric result.

Option C: Invalid. The expression unit_price || 5 attempts to concatenate a numeric value with a number, which is not valid without explicit conversion to a string. Moreover, the use of quotes around "Discount" is syntactically incorrect in this context.

Option D: Invalid. The expression expiry_date * 2 attempts to multiply a DATE datatype by a numeric value, which is not a valid operation.

Option E: Invalid. Similar to Option C, it incorrectly attempts to concatenate a number directly with a numeric value without conversion. Additionally, the aliasing with quotes is incorrectly placed.

Option F: Valid. This query simply adds two numeric columns (unit_price and surcharge), which is a valid and commonly used arithmetic operation in SQL.

Key components of an Entity-Relationship Model (ERM) include:

B. an attribute: Attributes are properties or characteristics of an entity, such as a person's name, date of birth, etc., and are essential in describing the data aspects of an entity in an ER model.

E. a relationship: Relationships describe how entities interact with each other within the database structure, such as a customer placing an order.

F. an entity: Entities are the key components of an ER model, representing objects or things within the domain that have a distinct existence, like 'Customer' or 'Order'.

Incorrect options:

A: A table is a database structure used to implement an entity in relational databases, not a component of the ER model itself.

C: While unique identifiers are crucial in database implementation (typically as primary keys), they are a specific attribute type, not a general component of ER models.

D: An activity is not a component of an ER model; activities relate more to process models or behavioral models in systems design.

A: This statement will not execute successfully because you cannot subtract a DAY interval from a DATE directly. SYSDATE needs to be cast to a TIMESTAMP first.

B: This statement is correct. It adds an interval of '1' DAY to the current TIMESTAMP.

C: This statement is correct. It subtracts an interval of '1' MINUTE from '1' DAY.

D: This statement will not execute successfully. In Oracle, you cannot add intervals of different date fields (DAY and MONTH) directly.

E: This statement has a syntax error with the quotes around INTERVAL and a misspelling, it should be 'INTERVAL'.

Oracle Database 12c SQL supports interval arithmetic as described in the SQL Language Reference documentation.