JDBC Objective Questions

See These Questions


1. Which statements about JDBC are true? (2 answers)
[a] JDBC is an API to connect to relational-, object- and XML data sources
[b] JDBC stands for Java DataBase Connectivity
[c] JDBC is an API to access relational databases, spreadsheets and flat files
[d] JDBC is an API to bridge the object-relational mismatch between OO programs and relational
databases


2. Which packages contain the JDBC classes?
 (a) java.jdbc and javax.jdbc
 (b) java.jdbc and java.jdbc.sql
 (c) java.sql and javax.sql
 (d) java.rdb and javax.rdb

3. Which type of driver provides JDBC access via one or more ODBC drivers?

 (a) Type 1 driver

 (b) Type 2 driver

 (c) Type 3 driver

 (d) Type 4 driver

4. Which type of driver converts JDBC calls into the network protocol used by the database management system

directly?

(a) Type 1 driver

(b) Type 2 driver

(c) Type 3 driver

(d) Type 4 driver

5. Which type of Statement can execute parameterized queries?

 (a) PreparedStatement

(b) ParameterizedStatement

 (c) ParameterizedStatement and CallableStatement

 (d) All kinds of Statements (i.e. which implement a sub interface of Statement)

6. How can you retrieve information from a ResultSet?

(a) By invoking the method get(..., String type) on the ResultSet, where type is the database type

(b) By invoking the method get(..., Type type) on the ResultSet, where Type is an object which represents a database

type

(c) By invoking the method getValue(...), and cast the result to the desired Java type.

(d) By invoking the special getter methods on the ResultSet: getString(...), getBoolean (...), getClob(...),...

7. How can you execute DML statements (i.e. insert, delete, update) in the database?

(a) By making use of the InsertStatement, DeleteStatement or UpdateStatement classes
(b) By invoking the execute(...) or executeUpdate(...) method of a normal Statement object or a sub-interface object
thereof
(c) By invoking the executeInsert(...), executeDelete(...) or executeUpdate(...) methods of the
DataModificationStatement object
(d) By making use of the execute(...) statement of the DataModificationStatement object


8. How do you know in your Java program that a SQL warning is generated as a result of executing a SQL statement in
the database?
 (a) You must catch the checked SQLException which is thrown by the method which executes the statement
(b) You must catch the unchecked SQLWarningException which is thrown by the method which executes the statement
(c) You must invoke the getWarnings() method on the Statement object (or a sub interface thereof)
(d) You must query the ResultSet object about possible warnings generated by the database


9. What is, in terms of JDBC, a DataSource?
 (a) A DataSource is the basic service for managing a set of JDBC drivers
 (b) A DataSource is the Java representation of a physical data source
 (c) A DataSource is a registry point for JNDI-services
 (d) A DataSource is a factory of connections to a physical data source


10. What is the meaning of ResultSet.TYPE_SCROLL_INSENSITIVE
 (a) This means that the ResultSet is insensitive to scrolling
 (b) This means that the Resultset is sensitive to scrolling, but insensitive to updates, i.e. not updateable
 (c) This means that the ResultSet is sensitive to scrolling, but insensitive to changes made by others
 (d) The meaning depends on the type of data source, and the type and version of the driver you use with this data source


11. Are ResultSets updateable?
 (a) Yes, but only if you call the method openCursor() on the ResultSet, and if the driver and database support this option
(b) Yes, but only if you indicate a concurrency strategy when executing the statement, and if the driver and database support this option
 (c) Yes, but only if the ResultSet is an object of class UpdateableResultSet, and if the driver and database support thisoption
 (d) No, ResultSets are never updateable. You must explicitly execute DML statements (i.e. insert, delete and update) to change the data in the underlying database


12. What statements are correct about JDBC transactions (2 correct answers)?
[a] A transaction is a set of successfully executed statements in the database
[b] A transaction is finished when commit() or rollback() is called on the Connection object,
[c] A transaction is finished when commit() or rollback() is called on the Transaction object
[d] A transaction is finished when close() is called on the Connection object.


13. How can you start a database transaction in the database?
 (a) By asking a Transaction object to your Connection, and calling the method begin() on it
 (b) By asking a Transaction object to your Connection, and setting the autoCommit property of the Transaction to false
 (c) By calling the method beginTransaction() on the Connection object
 (d) By setting the autoCommit property of the Connection to false, and execute a statement in the database


14. What is the meaning of the transaction isolation level TRANSACTION_REPEATABLE_READ
 (a) Dirty reads, non-repeatable reads and phantom reads can occur
 (b) Dirty reads are prevented; non-repeatable reads and phantom reads can occur
 (c) Dirty reads and non-repeatable reads are prevented; phantom reads can occur
 (d) Dirty reads, non-repeatable reads and phantom reads are prevented


15. What statements are correct about positioned updates (i.e. cursor updates) in ResultSets? (2
correct answers)
[a] Using the cursor technique is currently the only possible way to change the data in the current row of a ResultSet
[b] Insert statements are only supported when using scrollable cursors.
[c] Only scrollable updateable ResultSets can use this approach to change the data in the current row of a ResultSet
[d] The name of the cursor is specified by the setCursorName(String name) method the Statement object.


16. How can you execute a stored procedure in the database?
(a) Call method execute() on a CallableStatement object
(b) Call method executeProcedure() on a Statement object
(c) Call method execute() on a StoredProcedure object
(d) Call method run() on a ProcedureCommand object


17. What happens if you call the method close() on a ResultSet object?
 (a) the method close() does not exist for a ResultSet. Only Connections can be closed.
 (b) the database and JDBC resources are released
 (c) you will get a SQLException, because only Statement objects can close ResultSets
 (d) the ResultSet, together with the Statement which created it and the Connection from which the Statement was retrieved, will be closed and release all database and JDBC resources


18. What happens if you call deleteRow() on a ResultSet object?
 (a) The row you are positioned on is deleted from the ResultSet, but not from the database.
(b) The row you are positioned on is deleted from the ResultSet and from the database
(c) The result depends on whether the property synchronizeWithDataSource is set to true or false
(d) You will get a compile error: the method does not exist because you can not delete rows from a ResultSet


19. What statements are correct about batched insert and updates? (2 answers)
[a] To create a batch of insert and update statements, you create an object of type Batch, and call the method
addStatement(String statement) for each statement you want to execute in the batch
[b] Batch insert and updates are only possible when making use of parameterized queries.
[c] To do a batched update/insert, you call addBatch(String statement) on a Statement object for each statement you want to execute in the batch
[d] To execute a batched update/insert, you call the executeBatch() method on a Statement object


20. What is correct about DDL statements (create, grant,...)?
 (a) DDL statements are treated as normal SQL statements, and are executed by calling the execute() method on a Statement (or a sub interface thereof) object
 (b) To execute DDL statements, you have to install additional support files
 (c) DDL statements can not be executed by making use of JDBC, you should use the native database tools for this.
(d) Support for DDL statements will be a feature of a future release of JDBC


21. The JDBC-ODBC Bridge supports multiple concurrent open statements per connection?
a. True
b. False


22. Which of the following allows non repeatable read in JDBC Connection?
a. TRANSACTION_READ_UNCOMMITTED
b. TRANSACTION_READ_COMMITTED
c. TRANSACTION_SERIALIZABLE
d. TRANSACTION_REPEATABLE_READ


23. Which of the following statements is false as far as different type of statements is concern in JDBC?
a. Regular Statement
b. Prepared Statement
c. Callable Statement

d. Interim Statement

24. Which of the following methods are needed for loading a database driver in JDBC?
a. registerDriver() method
b. Class.forName()
c. Both A and B
d. getConnection()


25. Which of the following is false as far as type 4 driver is concern?
a. Type 4 driver is “native protocol, pure java” driver
b. Type 4 drivers are 100% Java compatible
c. Type 4 drivers uses Socket class to connect to the database
d. Type 4 drivers can not be used with Netscape


26. To execute a stored procedure “totalStock” in a database server, which of the following code snippet is used?
a. Statement stmt = connection.createStatement();stmt.execute("totalStock()");
b. CallableStatement clbstmnt = con.prepareCall("{call totalStock}");cs.executeQuery();
c. StoreProcedureStatement stmt=connection.createStoreProcedure("totalStock()");spstmt.executeQuery();
d. PrepareStatement pstmt = connection.prepareStatement("totalStock()");pstmt.execute();


27. Which driver is efficient and always preferable for using JDBC applications?
a. Type – 4
b. Type – 1
c. Type – 3
d. Type – 2


28. JDBC facilitates to store the java objects by using which of the methods of PreparedStatement
setObject () 2. setBlob() 3. setClob()
a. 1, 2
b. 1,2,3
c. 1,3
d. 2,3


29. Which statement is static and synchronized in JDBC API?
a. executeQuery()
b. executeUpdate()
c. getConnection()
d. prepareCall()


30. The JDBC-ODBC bridge is
a. Three tiered
b. Multithreaded
c. Best for any platform
d. All of the above


31. All raw data types (including binary documents or images) should be read and uploaded to the database as an array of
a. byte
b. int
c. boolean
d. char


32. The class java.sql.Timestamp has its super class as
a. java.sql.Time
b. java.util.Date
c. java.util.Time
d. None of the above


33. BLOB, CLOB, ARRAY and REF type columns can be updated in
a. JDBC 1.0
b. JDBC 4.0
c. JDBC 2.0
d. JDBC 3.0


34. Which of the following methods finds the maximum number of connections that a specific driver can obtain?
a. Database.getMaxConnections
b. Connection.getMaxConnections
c. DatabaseMetaData.getMaxConnections
d. ResultSetMetaData.getMaxConnections


35. Are prepared statements actually compiled?
a. Yes, they compiled
b. No, they are bound by the JDBC driver


36. When the message “No Suitable Driver” occurs?
a. When the driver is not registered by Class.forname() method
b. When the user name, password and the database does not match
c. When the JDBC database URL passed is not constructed properly
d. When the type 4 driver is used


37. Which driver is called as thin-driver in JDBC?
a. Type-4 driver
b. Type-1 driver
c. Type-3 driver
d. Type-2 driver


38. How many transaction isolation levels are defined in java.sql.Connection interface?
a. 4
b. 3
c. 5
d. 2


39. Which method is used to perform DML statements in JDBC?
a. execute()
b. executeQuery()
c. executeUpdate()
d. executeResult()


40. What is the disadvantage of Type-4 Native-Protocol Driver?
a. At client side, a separate driver is needed for each database.
b. Type-4 driver is entirely written in Java
c. The driver converts JDBC calls into vendor-specific database protocol
d. It does not support to read MySQL data.