Java & MySQL - Viewing a ResultSet


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The ResultSet interface contains dozens of methods for getting the data of the current row.

There is a get method for each of the possible data types, and each get method has two versions −

  • One that takes in a column name.

  • One that takes in a column index.

For example, if the column you are interested in viewing contains an int, you need to use one of the getInt() methods of ResultSet −

S.N. Methods & Description
1 public int getInt(String columnName) throws SQLException

Returns the int in the current row in the column named columnName.

2 public int getInt(int columnIndex) throws SQLException

Returns the int in the current row in the specified column index. The column index starts at 1, meaning the first column of a row is 1, the second column of a row is 2, and so on.

Similarly, there are get methods in the ResultSet interface for each of the eight Java primitive types, as well as common types such as java.lang.String, java.lang.Object, and java.net.URL.

There are also methods for getting SQL data types java.sql.Date, java.sql.Time, java.sql.TimeStamp, java.sql.Clob, and java.sql.Blob. Check the documentation for more information about using these SQL data types.

Following is the example which makes use of few viewing methods described.

This sample code has been written based on the environment and database setup done in the previous chapters.

Copy and paste the following example in TestApplication.java, compile and run as follows −

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class TestApplication {
   static final String DB_URL = "jdbc:mysql://localhost/TUTORIALSPOINT";
   static final String USER = "guest";
   static final String PASS = "guest123";
   static final String QUERY = "SELECT id, first, last, age FROM Employees";

   public static void main(String[] args) {
      // Open a connection
      try(Connection conn = DriverManager.getConnection(DB_URL, USER, PASS);
         Statement stmt = conn.createStatement(
         ResultSet.TYPE_SCROLL_INSENSITIVE,
         ResultSet.CONCUR_READ_ONLY);
         ResultSet rs = stmt.executeQuery(QUERY);
      ) {		
         // Move cursor to the last row.
         System.out.println("Moving cursor to the last...");
         rs.last();

         // Extract data from result set
         System.out.println("Displaying record...");
         //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);

         // Move cursor to the first row.
         System.out.println("Moving cursor to the first row...");
         rs.first();

         // Extract data from result set
         System.out.println("Displaying record...");
         // Retrieve by column name
         id  = rs.getInt("id");
         age = rs.getInt("age");
         first = rs.getString("first");
         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);
         // Move cursor to the first row.

         System.out.println("Moving cursor to the next row...");
         rs.next();

         // Extract data from result set
         System.out.println("Displaying record...");
         id  = rs.getInt("id");
         age = rs.getInt("age");
         first = rs.getString("first");
         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);		

      } catch (SQLException e) {
         e.printStackTrace();
      } 
   }
}

Now let us compile the above example as follows −

C:\>javac TestApplication.java
C:\>

When you run TestApplication, it produces the following result −

C:\>java TestApplication
Moving cursor to the last...
Displaying record...
ID: 103, Age: 30, First: Sumit, Last: Mittal
Moving cursor to the first row...
Displaying record...
ID: 100, Age: 18, First: Zara, Last: Ali
Moving cursor to the next row...
Displaying record...
ID: 101, Age: 25, First: Mehnaz, Last: Fatma
C:\>
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