In Oracle SQL, when performing a JOIN operation, the ON clause is used to specify the condition that relates the two tables being joined. The WHERE clause can be used to further filter the result set.
A) This is a valid join condition using the WHERE clause to filter the rows after the join has been made.
B) This statement will fail because the ON clause should only contain conditions that relate the two tables. The condition for filtering the departments table should be in the WHERE clause, not in the ON clause. This is a common mistake when writing JOIN statements.
C) This is a correct statement. The ON clause specifies how the tables are related and the WHERE clause specifies an additional filtering condition for the query.
D) This statement is also correct. It's similar to the first statement (A) and properly places the department_id filter in the ON clause, which is acceptable though not typically best practice as it can be less readable than using a WHERE clause for non-join conditions.
When the JOIN operation is executed, the database first pairs rows from the joined tables that meet the join condition specified by the ON clause. Then, it filters the result of the JOIN operation based on the condition specified in the WHERE clause.
Which two queries will return a list of countries with no departments?
A)
B)
C)
D)
Answer : B, D
The query's goal is to return a list of countries that have no departments linked to them.
Option B and Option D are the correct answers because they use set operations that will effectively return countries that do not have a corresponding entry in the departments table:
Option B uses the NOT IN subquery to exclude countries that have departments linked to them. It looks for country_id values in the countries table that are not present in the list of country_id values associated with locations that are, in turn, associated with departments. This will correctly return countries that have no departments.
Option D uses the MINUS set operator, which subtracts the results of the second SELECT statement from the results of the first. This statement will return all countries from the countries table minus those that have an associated department_id in the departments table, effectively listing countries with no departments.
Option A and Option C are incorrect because:
Option A will not execute successfully as it tries to join tables using a column (country_id) that doesn't exist in the departments table, which will lead to an error.
Option C's use of INTERSECT is incorrect for this requirement. INTERSECT returns only the rows that exist in both queries. Since we want countries with no departments, using INTERSECT would actually return the opposite of what is required.
Therefore, the correct options are B and D, which use subquery exclusion and the MINUS set operator, respectively, to accurately identify and return countries without departments.
A . False. Constraints are enforced during INSERT and UPDATE operations, and by the nature of their definition, they impact DELETE operations as well (in the case of referential constraints).
B . False. A column with a foreign key constraint can contain a NULL value unless it is also constrained to be NOT NULL.
C . False. Not all constraints can be defined at the column level. For example, some constraints such as FOREIGN KEY constraints are more commonly defined at the table level.
D . True. A constraint can be disabled regardless of whether the constrained column contains data. However, re-enabling the constraint requires that all data satisfy the constraint rules.
E . True. A column with a UNIQUE constraint can indeed contain a NULL value, as NULL is considered not equal to any value, including itself. This means that multiple rows with NULL values do not violate the UNIQUE constraint.
B . The first statement will not display departments with no employees since it does not use a join that includes departments without matching employee records.
D . As explained, the first statement will not display departments with no employees.
E . There is a typo in the option; it should be E.AVG_SAL. Even if corrected, the first statement alone would not execute successfully because it does not include a join to bring in the avg_sal value.
F . The second statement will display departments with no employees, but the first statement will not, so this option is incorrect.
Which three statements are true about single-row functions?
Answer : A, B, E
Single-row functions in SQL return one result per row, and the following statements are true:
A: The data type of the returned value can indeed be different from the data type of the argument provided to the function. For example, the TO_CHAR function can take a numeric input and return a character string.
B: Single-row functions can be nested within each other to any level that is supported by Oracle. This means you can have a function call as an argument to another function, and so on.
E: The argument to a single-row function can be a column name, a variable, a literal, or an expression. This flexibility allows these functions to be very powerful in SQL expressions.
The incorrect options are:
C: Single-row functions do not return a single result row per table; they return a result for each row that is processed.
D: They are not limited to accepting only one argument. Some functions, like NVL, accept multiple arguments.
F: They are not limited to use in the WHERE clause; single-row functions can be used in any part of a SQL statement, including SELECT and ORDER BY clauses.
Unlock All Features of Oracle 1Z0-071 Dumps Software
Just have a look at the best and updated features of our 1Z0-071 dumps which are described in detail in the following tabs. We are very confident that you will get the best deal on this platform.
Select Question Types you want
Set your desired pass percentage
Allocate Time (Hours: Minutes)
Create Multiple Practice test with limited questions
Customer Support
Latest Success Metrics For actual 1Z0-071 Exam
This is the best time to verify your skills and accelerate your career. Check out last week's results, more than 90% of students passed their exam with good scores. You may be the Next successful Candidate.
95%
Average Passing Scores in final Exam
91%
Exactly Same Questions from these dumps
90%
Customers Passed Oracle 1Z0-071 exam
OUR SATISFIED CUSTOMER REVIEWS
David Smith
November 7, 2024
When I got registered for Oracle 1Z0-071 exam, I was so afraid even to try. I gave-up initially, but then I found Premiumumps and today I am proud to make a right decision. I only spend 7 days in preparation, but the result was unanticipated. I got 100% marks and finally advanced my credentials.
João Silva
November 6, 2024
I would like to share, initially I was not sure if I could pass the Oracle Database SQL exam, because I didn’t get time to prepare for it. But Premiumdumps Practice exam helped me to fulfill my dream. The user friendly interface made be acquainted with the actual exam by offering the real exam simulation. I give all credits to Premiumdumps.
Jacinda Ardern
November 3, 2024
I have recently passed Oracle 1Z0-071 exam with the excellent results, on the first attempt. I owe thanks to Premiumdumps, who helped to become certified Professional.
Grim
November 1, 2024
Premiumdumps Practice Questions have been a help for me whilst preparing for my Oracle 1Z0-071 test. I wanted to have 99% marks in the test and I did! Thanks to Premiumdumps!
Lily Anne
October 31, 2024
My colleague suggested me to attempt Oracle 1Z0-071 exam and prepare it with premiumdumps. I feel lucky, I attempted exam only with experts made practice questions
Yuko Tanaka
October 28, 2024
Premiumsdumps practice questions prepared me well for my Oracle 1Z0-071 exams. And helped me to eliminate the exam anxiety. I didn’t feel any pressure while in the exam, because the practice exam of Premiumdumps was quite similar and helped me to pass exam on the first try.
Emma Grace
October 26, 2024
Premiumdumps is a reliable and trustworthy platform, which enabled me to pass 1Z0-071. I am grateful that I only trusted Premiumdumps.