Exam 98-364 Topic 5 Question 67 Discussion

COMMIT statement is a transaction control statement that ends the current database
transaction and makes all changes made in that transaction permanent. It also releases all
locks on the transaction.
The TRUNCATE statement is a Data Definition Language (DDL) statement that is used to
remove all records from a table. It also releases the storage space used by the table. The
TRUNCATE statement cannot be rolled back.
Syntax:
TRUNCATE TABLE TableName;
Therefore, both the commands, COMMIT and TRUNCATE, can never be rolled back.
Note: The TRUNCATE command includes a built-in COMMIT command.
Answer C and A are incorrect. The SQL UPDATE statement allows a user to update the
current values in a database with new values.
It contains three main clauses. The first clause specifies the table that requires an update,
the second clause specifies the column name and the data values that will be inserted in
place of the current values, and the third clause specifies the criteria for the records that
will be updated. An example query is given below:
Update Employee{first clause}
Set Fname="Roger"{second clause}
Lname="Pressman"
WHERE Empid=1{third clause}
The DELETE statement is a Data Manipulation Language (DML) statement that is used to
delete records from a table, based on the condition specified in the WHERE clause. If the
WHERE clause is omitted, all records in the table are deleted. The DELETE statement can
be rolled back.
Syntax:
DELETE [FROM] TableName
[WHERE condition];
The above two DML commands can therefore be rolled back.