In this article, we will learn some of the core components of JDBC

JDBC Core components :

1. DriverManager
2. Driver
3. Connection
4. Statement
5. ResultSet

1. DriverManager :

• DriverManager is a mean through which it connects to databases using appropriate driver supplied from Java application
• DriverManager registers all driver requests comes from Java application and picks up appropriate driver to connect to database

public static void registerDriver(Driver driver);

• DriverManager has number of useful static methods to get connection objects, these are

public static Connection getConnection(String dbUrl); 
public static Connection getConnection(String dbUrl, String username,String password); 
public static Connection getConnection(String dbUrl, Properties props);

2. JDBC Driver :

• Drivers are the one which actually communicates with the databases
• But user generally never interact with drivers directly
• Instead, user go through DriverManager to register and de-register drivers and then communicate with database

3. Connection :

• After registering drivers, DriverManager has got number of static getConnection() method to return Connection object
• It is only after successfully getting connection object, user can interact with database
• Connection interface also got some useful methods like setAutoCommit(boolean), commit(), rollback() methods to handle transaction
• Using connection object, we can create/prepare all three types of statements i.e.;

createStatement(); // for Statement 
prepareStatement(); // for PreparedStatement 
prepareCall();  // for CallableStatement

4. Statement :

• Statement interface is the one which is actually used to execute queries like inserting new record or updating an existing record
• executeQuery(String sqlQuery); and executeUpdate(String sqlQuery) are the most commonly used methods from Statement interface
• executeQuery(String sqlQuery); returns object of ResultSet
• There is also executeBatch(); method for batch execution

5. ResultSet :

• ResultSet holds data retrieved from database when performing/executing queries (both SQL and MySQL)
• You can traverse in ResultSet to read data one-by-one, but in forward direction only
• But by setting static variable “TYPE_SCROLL_INSENSITIVE” in createStatement(), we can make it scrollable in both directions
• Similarly, by setting static variable “CONCUR_UPDATABLE” in createStatement(), we can make ResultSet updatable, as it is not updatable by default

Related Articles :

• Java – Introduction to JDBC
• Java – JDBC Driver types
• Java – Core JDBC components
• Java – JDBC Driver list for all leading database
• Java – JDBC connection steps
• Java – An example to connect MySQL database
• Java – An example to connect Oracle database
• Java – An example to connect MS Access database
• Java 8 – An example to connect MS Access database in Java 8
• Java – JDBC program to connect IBM DB2 database running on Mainframe z/OS system
• Java – Creating database using JDBC Statement interface
• Java – Droping database using JDBC Statement interface
• Java – Creating a table using JDBC Statement interface
• Java – Inserting a record using JDBC Statement interface
• Java – Getting all list of records using JDBC Statement interface
• Java – Getting single record using JDBC Statement interface
• Java – Updating a record using JDBC Statement interface
• Java – Deleting a record using JDBC Statement interface
• Java – Dropping a table using JDBC Statement interface
• Java – Batch update using JDBC Statement interface
• Java – Batch insert using JDBC Statement interface
• Java – Creating a table using JDBC PreparedStatement interface
• Java – Inserting a record using JDBC PreparedStatement interface
• Java – Getting all list of records using JDBC PreparedStatement interface
• Java – Getting single record using JDBC PreparedStatement interface
• Java – Updating a record using JDBC PreparedStatement interface
• Java – Deleting a record using JDBC PreparedStatement interface
• Java – Batch update using JDBC PreparedStatement interface
• Java – Batch insert using JDBC PreparedStatement interface
• Java – Calling Stored Procedure using JDBC CallableStatement interface
• Java – Calling Stored Function using JDBC CallableStatement interface
• Java – Calling Stored Procedure using JDBC CallableStatement interface with Batch execution
• Java – Transaction handling using JDBC Statement interface
• Java – Transaction handling using JDBC PreparedStatement interface
• Java – Integration with Spring framework (Spring JDBC)
• Java – Where clause example using JDBC Statement interface
• Java – Like clause example using JDBC Statement interface
• Java – Order by clause example using JDBC Statement interface
• Java – Metadata of database using JDBC DatabaseMetaData interface
• Java – Metadata of Resultset using JDBC ResultSetMetaData interface
• Java – Interview question and answer on JDBC

References :

• https://docs.oracle.com/javase/tutorial/jdbc/basics/gettingstarted.html
• https://docs.oracle.com/cd/E11882_01/java.112/e16548/overvw.htm#JJDBC28025
• http://docs.oracle.com/javase/tutorial/jdbc/basics/index.html
• https://en.wikipedia.org/wiki/JDBC_driver
• http://www.devx.com/tips/Tip/28818
• https://docs.oracle.com/javase/7/docs/api/java/lang/Class.html#forName(java.lang.String)

Happy Coding !!
Happy Learning !!