data cannot contain multiple tables
Answers
Answer:
yes.
Explanation:
yes ,it contain multiple tables and relationship between thetables
Answer:
1.Which of the following is not related to a Relational Database?
Selection
Projection
Joining
None of the above
Answer: D. The options A, B and C are the major capabilities of the Oracle Relational Database.
2.Which of the following methods is used for writing a query with columns from multiple tables?
SELECT
GROUP BY
ORDER BY
JOINS
Answer: D. Joins are used to connect multiple tables and project column data from multiple tables in Oracle.
3.Which of the following is one of the most common methods to join multiple tables?
Hash Join
Equijoin
Self Join
Cross Join
Answer: B. Equijoin is one of the types of joins which is the most common and simple technique for joining more than one tables. Equijoins are also called simple joins or inner joins.Equijoin involve primary key and foreign key.
4.Which of following will be used to join rows with other tables if the column values fall in a range defined by inequality operators?
Equijoin
Simple join
Non-equijoin
None of the above
Answer: C. Equijoins use equality operators to join rows, non-equijoins use inequality operators.
5.Which of the following statements is true about Oracle joins?
NULL values are included in the result set
Only the rows which have matching conditions are fetched
All the rows that are present in any of the one tables are fetched
None of the above
Answer: B. NULL values and differing entries in common join columns are excluded when joins are used.
6.Which of the following can be used to join the rows of a table with other rows of the same table?
Equijoin
Non-equijoin
Outer join
Self-join
Answer: D. The association is based on columns with logical and usually hierarchical relationships with each other.
7.What is true about a cartesian join of two tables in Oracle DB?
It must be avoided as it is costly and non optimized
It is formed when every row from one table is joined with all rows in the second table
Both A and B
None of the above
Answer: B. Cartesian join is often the result of missing or inadequate join conditions.It is simply the cross product of two tables.
8.Which of the following is one of the basic types of joins in Oracle DB ?
Outer join
Self-join
Equi-join
All of the above
Answer: C. Equi-join and non-equijoin are the two basic types of joins in Oracle DB.
9.What is the main condition for using joins between a source table and a target table in Oracle DB for getting a non-cartesian product result?
There is no condition
At least one of the columns in both the tables should be common.
The names of the columns in both the joining tables should be the same for using joins
None of the above
Answer: B. The tables must be connected through a common column relating two entities.The table joined on a common column produce