JDBC Interview Questions and Answers

What is JDBC Driver ?
The JDBC Driver provides vendor-specific implementations of the abstract classes provided by the JDBC API. This driver is used to connect to the database.
Post comment
Thanks for your comment.!
Write a comment(Click here) ...
What is JDBC?
JDBC technology is an API that provides cross-DBMS connectivity to a wide range of SQL databases and access to other tabular datasources, such as spreadsheets or flat files. With a JDBC technology-enabled driver, you can connect all corporate data even in a heterogeneous environment.
What are the steps required to execute a query in JDBC?
First we need to create an instance of a JDBC driver or load JDBC drivers, then we need to register this driver with DriverManager class. Then we can open a connection. By using this connection , we can create a statement object and this object will help us to execute the query.
What is DriverManager ?
DriverManager is a class in java.sql package. It is the basic service for managing a set of JDBC drivers.
What is a ResultSet ?
A table of data representing a database result set, which is usually generated by executing a statement that queries the database. ResultSet object maintains a cursor pointing to its current row of data. Initially the cursor is positioned before the first row. The next method moves the cursor to the next row, and because it returns false when there are no more rows in the ResultSet object, it can be used in a while loop to iterate through the result set.
What is Connection?
Connection class represents a connection (session) with a specific database. SQL statements are executed and results are returned within the context of a connection. Connection object's database is able to provide information describing its tables, its supported SQL grammar, its stored procedures, the capabilities of this connection, and so on. This information is obtained with the getMetaData method.
What does Class.forName return?
class as loaded by the classloader.

What is Connection pooling?
A Connection pooling is a technique used for sharing server resources among requesting clients. Connection pooling increases the performance of Web applications by reusing active database connections instead of creating a new connection with every request. Connection pool manager maintains a pool of open database connections.
What are the different JDBC drivers available?

There are mainly four type of JDBC drivers available. 
Type 1 : JDBC-ODBC Bridge Driver - A JDBC-ODBC bridge provides JDBC API access via one or more ODBC drivers. Note that some ODBC native code and in many cases native database client code must be loaded on each client machine that uses this type of driver. Hence, this kind of driver is generally most appropriate when automatic installation and downloading of a Java technology application is not important. For information on the JDBC-ODBC bridge driver provided by Sun. 

Type 2: Native API Partly Java Driver- A native-API partly Java technology-enabled driver converts JDBC calls into calls on the client API for Oracle, Sybase, Informix, DB2, or otherDBMS. Note that, like the bridge driver, this style of driver requires that some binary code be loaded on each client machine. 

Type 3: Network protocol Driver- A net-protocol fully Java technology-enabled driver translates JDBC API calls into a DBMS-independent net protocol which is then translated to a DBMS protocol by a server. This net server middleware is able to connect all of its Java technology-based clients to many different databases. The specific protocol used depends on the vendor. In general, this is the most flexible JDBC API alternative. It is likely that all vendors of this solution will provide products suitable for Intranet use. In order for these products to also support Internet access they must handle the additional requirements for security, access through firewalls, etc., that the Web imposes. Several vendors are adding JDBC technology-based drivers to their existing database middleware products. 

Type 4: JDBC Net pure Java Driver - A native-protocol fully Java technology-enabled driver converts JDBC technology calls into the network protocol used by DBMSs directly. This allows a direct call from the client machine to the DBMS server and is a practical solution for Intranet access. Since many of these protocols are proprietary the database vendors themselves will be the primary source for this style of driver. Several database vendors have these in progress.

Which is the fastest type of JDBC driver?

Type 4 (JDBC Net pure Java Driver) is the fastest JDBC driver. Type 1 and Type 3 drivers will be slower than Type 2 drivers (the database calls are make at least three translations versus two), and Type 4 drivers are the fastest (only one translation).

Is the JDBC-ODBC Bridge multi-threaded?
No. The JDBC-ODBC Bridge does not support multi threading. The JDBC-ODBC Bridge uses synchronized methods to serialize all of the calls that it makes to ODBC. Multi-threaded Java programs may use the Bridge, but they won't get the advantages of multi-threading.
How do you handle your own transaction ?
Connection Object has a method called setAutocommit ( boolean flag) . For handling our own transaction we can set the parameter to false and begin your transaction . Finally commit the transaction by calling the commit method.

Latest Updates


First we increased the denominator of a positive fraction by 3 and then decrease it by 5.The sum of the resulting fractions proves to be equal to 2/3. Find the denominator of the fraction if its numerator is 2?


If we divide a two digit number by the sum of its digits we get 4 as a quotient and 3 as a remainder. Now if we divide that two digit number by the product of its digits we get 3 as a quotient and 5 as a remainder . Find the two digit number?


The denominators of an irreducible fraction is greater than the numerator by 2.If we reduce the numerator of the reciprocal fraction by 3 and subtract the given fraction from the resulting one,we get 1/15.Find the given fraction?


If we add the square of the digit in the tens place of the positive two digit number to the product of the digits of that number we get 52,and if we add the square of the digit in the unit's place to the same product of the digits we get 117.Find the two digit number?

The sum of squares of the digits constituting a positive two digit number is 13, If we subtract 9 from that number we shall get a number written by the same digits in the reverse order. Find the number?

The arithmetic mean of two numbers is smaller by 24 than the larger of the two numbers and the GM of the same numbers exceeds by 12 the smaller of the numbers. Find the numbers?

A number being successively divided by 3,5,8 leaves remainder 1,4,7 respectively. Find the respective remainders if the order of divisors are reversed?

The sum of all possible two digit numbers formed from three different one digit natural numbers when divided by the sum of the original three numbers is equal to?


Find the HCF and LCM of the polynomial x2-5x+6 and x2-7x+10?


When we multiply a certain two digit number by the sum of its digits , 405 is achieved. If we multiply the number written in reverse order of the same digits by the sum of the digits, we get 486. Find the number?


The sum of two numbers is 15 and their geometric mean is 20% lower than their arithmetic mean. Find the numbers?


The difference of 1025-7 and 1024+x is divisible by 3. find x=?

A number when divided by the sum of 555 and 445 gives two times their difference as quotient and 30 as remainder . The number is?

The sum of three prime numbers is 100.If one of them exceeds another by 36 then one of the numbers is?

Find the number of zeros in the factorial of the number 18?

If a number is multiplied by 22 and the same number is added to it then we get a number that is half the square of that number. Find the number?

In doing a division of a question with zero remainder,a candidate took 12 as divisor instead of 21.The quotient obtained by him was 35. The correct quotient is?


A number when divided by 342 gives a remainder 47.When the same number is divided by 19 what would be the remainder?

Latest Job Notifications

Jobs in West Bengal

इंडियन पोस्ट सर्विस Indian Post Service - 2357 पद - 19/08/2021 अंतिम तिथि - पश्चिम बंगाल पोस्टल सर्कल

Banking Jobs

भारतीय स्टेट बैंक State Bank of India(SBI) - 6100 पद - 26/07/2021 अंतिम तिथि - CRPD/APPR/2021-22/10

SSC Recruitment

कर्मचारी चयन आयोग Staff Selection Commission(SSC) - 25271 पद - 31/08/2021 अंतिम तिथि

Jobs in Madhya Pradesh

राष्ट्रीय स्वास्थ्य मिशन मध्य प्रदेश National Health Mission MP(NRHM) - 5215 पद - 22/06/2021 अंतिम तिथि

Jobs in Punjab

पंजाब स्टेट पावर कॉर्पोरेशन लिमिटेड Punjab State Power Corporation Limited (PSPCL) - 2632 पद - 20/06/2021 अंतिम तिथि

Jobs in Chhattisgarh

स्वास्थ्य सेवा निदेशालय, छत्तीसगढ़ Department of Health & Family Welfare, Chhattisgarh - 267 पद - 26/06/2021 अंतिम तिथि

Government Jobs

दिल्ली सबऑर्डिनेट सर्विस सिलेक्शन बोर्ड Delhi Subordinate Services Selection Board(DSSSB) - 5807 पद - 03/07/2021 अंतिम तिथि

Jobs in Madhya Pradesh

राष्ट्रीय स्वास्थ्य मिशन मध्य प्रदेश National Health Mission MP(NRHM) - 2850 पद - 31/05/2021 अंतिम तिथि

Government Jobs

इंडियन पोस्ट सर्विस Indian Post Service - 4368 पद - 29/05/2021 अंतिम तिथि

दिल्ली सबऑर्डिनेट सर्विस सिलेक्शन बोर्ड Delhi Subordinate Services Selection Board(DSSSB) - 7236 पद - 24/06/2021 अंतिम तिथि