Java JDBC - Update a Column in a Table - GeeksforGeeks

08 Dec, 2020
Java has its own API which JDBC API which uses JDBC drivers for database connections. JDBC API provides the applications-to-JDBC connection and JDBC driver provides a manager-to-driver connection. Following are the 5 important steps to connect java application to our database using JDBC.
Registering the Java class
Creating a Connection
Creating a Statement
Executing queries
Closing connection
Note: Load mysqlconnector.jar into your program.
Steps:
Download MySQLConnect/J (JDBC connector jar file) from the following link  https://dev.mysql.com/downloads/connector/j
Select platform-independent in select OS option
Copy mysql-connector-java-5.1.34-bin.jar file in your project
Right-click on it , select Build Path-> Configure Build path -> libraries -> Add JARS
In JAR selection window, select mysql-connector-java-5.1.34-bin.jar library under your project
Click OK
Create a Database, add a table with records using MySQL cmd.  
Java
// Update a Column in a Table  // dont forget to import below packageimport java.sql.*;  public class Database {        // url that points to mysql database, 'db' is database    // name    static final String url        = "jdbc:mysql://localhost:3306/db";      public static void main(String[] args)        throws ClassNotFoundException    {        try {            // this Class.forName() method is user for            // driver registration with name of the driver            // as argument i have used MySQL driver            Class.forName("com.mysql.jdbc.Driver");              // getConnection() establishes a connection. It            // takes url that points to your database,            // username and password of MySQL connections as            // arguments            Connection conn = DriverManager.getConnection(                url, "root", "1234");              // create.Statement() creates statement object            // which is responsible for executing queries on            // table            Statement stmt = conn.createStatement();              // Executing the query, student is the table            // name and RollNo is the new column            String query                = "ALTER TABLE student RENAME COLUMN roll_no TO RollNo";              // executeUpdate() is used for INSERT, UPDATE,            // DELETE statements.It returns number of rows            // affected by the execution of the statement            int result = stmt.executeUpdate(query);              // if result is greater than 0, it means values            // has been added            if (result > 0)                System.out.println(                    "table successfully updated.");            else                System.out.println("unable to update");              // closing connection            conn.close();        }        catch (SQLException e) {            System.out.println(e);        }    }}
JDBC
Picked
Technical Scripter 2020
Java
Java Programs
Technical Scripter
Java
Writing code in comment?
Please use ide.geeksforgeeks.org,
generate link and share the link here.
Comments
Old Comments
Different ways of Reading a text file in Java
Constructors in Java
Stream In Java
Exceptions in Java
StringBuilder Class in Java with Examples
Convert a String to Character array in Java
Java Programming Examples
Convert Double to Integer in Java
Implementing a Linked List in Java using Class
How to Iterate HashMap in Java?