Oracle Certification Questions

Q:

How many joining conditions are required to join 4 tables in SQL?

A) 1 B) 2
C) 3 D) 4
 
Answer & Explanation Answer: C) 3

Explanation:

To join 'n' tables 'n-1' conditions should be satisfied.

So to join 4 tables 3 conditions should be satisfied.

Report Error

View Answer Workspace Report Error Discuss

4 4480
Q:

What is the maximum number of triggers, can apply to a single table?

A) 8 B) 10
C) 12 D) 14
 
Answer & Explanation Answer: C) 12

Explanation:

Maximim number of triggers that can be applied to a single table is 12

Report Error

View Answer Workspace Report Error Discuss

6 3656
Q:

Breaking of relationships is allowed once referential integrity on a database is enforced

A) TRUE B) FALSE
Answer & Explanation Answer: B) FALSE

Explanation:

Breaking of relationships is prevented once referential integrity on a database is enforced

Report Error

View Answer Workspace Report Error Discuss

0 2798
Q:

A column defined as UNIQUE can contain Nulls while a column defined as PRIMARY KEY can't contain Nulls

A) TRUE B) FALSE
Answer & Explanation Answer: A) TRUE

Explanation:

Because a table can have only one primary key

Report Error

View Answer Workspace Report Error Discuss

1 2756
Q:

Which dml command is used in conjunction with @@identity?

A) INSERT and UPDATE B) UPDATE and DELETE
C) SCOPE_IDENTITY and IDENT_CURRENT D) Commit and rollback
 
Answer & Explanation Answer: C) SCOPE_IDENTITY and IDENT_CURRENT

Explanation:

Using automatically incrementing IDENTITY columns is very popular with database developers. You don’t need to explicitly calculate unique surrogate keys when inserting new data, the IDENTITY column functionality does that for you. The IDENTITY feature also allows you to specify useful Seed and Increment properties. When you use an INSERT statement to insert data into a table with an IDENTITY column defined, SQL Server will generate a new IDENTITY value.

 

You can use the @@IDENTITY variable and the SCOPE_IDENTITY and IDENT_CURRENT functions to return the last IDENTITY value that has been generated by SQL Server. This is very useful when you need to return the key for the row that has just been inserted, back to the caller.

Report Error

View Answer Workspace Report Error Discuss

7 2667
Q:

Which among the following keys are used to identify each row of the table uniquely?

A) Primary key B) Unique key
C) Partial key D) None of the above
 
Answer & Explanation Answer: A) Primary key

Explanation:

Primary key helps us to identify a row uniquely in a relation

Report Error

View Answer Workspace Report Error Discuss

2 2453
Q:

What is the default return value of a function?

A) int B) char
C) string D) None of the above
 
Answer & Explanation Answer: A) int

Explanation:

The default return value from a function is int. In other words, unless explicitly specified the default return value by compiler would be integer value from function.

Report Error

View Answer Workspace Report Error Discuss

3 2407
Q:

The SQL keyword(s) ________ is used with wildcards.

A) LIKE only B) IN only
C) NOT IN only D) IN and NOT IN
 
Answer & Explanation Answer: A) LIKE only

Explanation:
Report Error

View Answer Workspace Report Error Discuss

1 2317