https://github.com/imranhsayed/programming-in-java

Example programs in Java
https://github.com/imranhsayed/programming-in-java

python python-examples python-exercises

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Example programs in Java

• Host: GitHub
• URL: https://github.com/imranhsayed/programming-in-java
• Owner: imranhsayed
• License: gpl-3.0
• Created: 2022-09-18T11:38:49.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2022-10-12T05:26:16.000Z (about 2 years ago)
• Last Synced: 2024-10-02T10:41:58.342Z (3 months ago)
• Topics: python, python-examples, python-exercises
• Language: Java
• Homepage:
• Size: 29.3 KB
• Stars: 4
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# programming-in-java

Example programs in Java

# What is ResultSet In Java?

* ResultSet is an interface in Java that is used to get the database result in a table format. 

* The object of ResultSet maintains a cursor pointing to a row of a table. Initially, cursor points to before the first row.

* But we can make this object to move forward and backward direction by passing either TYPE_SCROLL_INSENSITIVE or TYPE_SCROLL_SENSITIVE in createStatement(int,int) method as well as we can make this object as updatable by:

```java

Statement stmt = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,  

                     ResultSet.CONCUR_UPDATABLE);  

```

* Example

```java

import java.sql.*;  

class FetchRecord{  

public static void main(String args[])throws Exception{  

  

Class.forName("oracle.jdbc.driver.OracleDriver");  

Connection con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","system","oracle");  

Statement stmt=con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);  

ResultSet rs=stmt.executeQuery("select * from emp765");  

  

//getting the record of 3rd row  

rs.absolute(3);  

System.out.println(rs.getString(1)+" "+rs.getString(2)+" "+rs.getString(3));  

  

con.close();  

}}  

```

* Another example

```java

/STEP 1. Import required packages

import java.sql.*;

public class Main{

   // JDBC driver name and database URL

   static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";  

   static final String DB_URL = "jdbc:mysql://localhost/STUDENTS";

   //  Database credentials

   static final String USER = "username";

   static final String PASS = "password";

   

   public static void main(String[] args) {

   Connection conn = null;

   Statement stmt = null;

   try{

      //STEP 2: Register JDBC driver

      Class.forName("com.mysql.jdbc.Driver");

      //STEP 3: Open a connection

      System.out.println("Connecting to a selected database...");

      conn = DriverManager.getConnection(DB_URL, USER, PASS);

      System.out.println("Connected database successfully...");

      

      //STEP 4: Execute a query

      System.out.println("Creating statement...");

      stmt = conn.createStatement();

      String sql = "SELECT id, first, last, age FROM Registration";

      ResultSet rs = stmt.executeQuery(sql);

      //STEP 5: Extract data from result set

      while(rs.next()){

         //Retrieve by column name

         int id  = rs.getInt("id");

         int age = rs.getInt("age");

         String first = rs.getString("first");

         String last = rs.getString("last");

         //Display values

         System.out.print("ID: " + id);

         System.out.print(", Age: " + age);

         System.out.print(", First: " + first);

         System.out.println(", Last: " + last);

      }

      rs.close();

   }catch(SQLException se){

      //Handle errors for JDBC

      se.printStackTrace();

   }catch(Exception e){

      //Handle errors for Class.forName

      e.printStackTrace();

   }finally{

      //finally block used to close resources

      try{

         if(stmt!=null)

            conn.close();

      }catch(SQLException se){

      }// do nothing

      try{

         if(conn!=null)

            conn.close();

      }catch(SQLException se){

         se.printStackTrace();

      }//end finally try

   }//end try

   System.out.println("Goodbye!");

}//end main

}//end Class

```