How to get the row count from ResultSet in JDBC


Whenever we execute SQL statements using the executeQuery() method, it returns a ResultSet object which holds the tabular data returned by the SELECT queries(in general). The ResultSet object contains a cursor/pointer which points to the current row. Initially this cursor is positioned before first row (default position).

The ResultSet interface provides various methods to find, the no.of columns, name of the column, type of the column etc.. but, it does not provides any method to find the number of rows in a table directly.

Using count(*) function in the SELECT query you can get the number of rows in a table as −

select count(*) from Table_Name;

Let us create a table with name MyPlayers in MySQL database using CREATE statement as shown below −

CREATE TABLE MyPlayers(
   ID INT,
   First_Name VARCHAR(255),
   Last_Name VARCHAR(255),
   Date_Of_Birth date,
   Place_Of_Birth VARCHAR(255),
   Country VARCHAR(255),
   PRIMARY KEY (ID)
);

Now, we will insert 7 records in MyPlayers table using INSERT statements −

insert into MyPlayers values(1, 'Shikhar', 'Dhawan', DATE('1981-12-05'), 'Delhi', 'India');
insert into MyPlayers values(2, 'Jonathan', 'Trott', DATE('1981-04-22'), 'CapeTown', 'SouthAfrica');
insert into MyPlayers values(3, 'Kumara', 'Sangakkara', DATE('1977-10-27'), 'Matale', 'Srilanka');
insert into MyPlayers values(4, 'Virat', 'Kohli', DATE('1988-11-05'), 'Delhi', 'India');
insert into MyPlayers values(5, 'Rohit', 'Sharma', DATE('1987-04-30'), 'Nagpur', 'India');
insert into MyPlayers values(6, 'Ravindra', 'Jadeja', DATE('1988-12-06'), 'Nagpur', 'India');
insert into MyPlayers values(7, 'James', 'Anderson', DATE('1982-06-30'), 'Burnley', 'England');

Following JDBC program finds the number of rows in the above table and displays the value.

Example

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class RS_Row_Count {
   public static void main(String args[]) throws Exception {
      //Registering the Driver
      DriverManager.registerDriver(new com.mysql.jdbc.Driver());
      //Getting the connection
      String mysqlUrl = "jdbc:mysql://localhost/mydatabase";
      Connection con = DriverManager.getConnection(mysqlUrl, "root", "password");
      System.out.println("Connection established......");
      //Creating a Statement object
      Statement stmt = con.createStatement();
      //Retrieving the data
      ResultSet rs = stmt.executeQuery("select count(*) from MyPlayers");
      rs.next();
      //Moving the cursor to the last row
      System.out.println("Table contains "+rs.getInt("count(*)")+" rows");
   }
}

Output

Connection established......
Table contains 8 rows

Getting the number of rows using methods

The last() method of the ResultSet interface moves the cursor to the last row of the ResultSet and, the getRow() method returns the index/position of the current row.

Therefore, to get the number of rows move the cursor to the last row using the last() method and get the position of that (last) row using the getRow() method.

Example

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class RS_Row_Count {
   public static void main(String args[]) throws Exception {
      //Registering the Driver
      DriverManager.registerDriver(new com.mysql.jdbc.Driver());
      //Getting the connection
      String mysqlUrl = "jdbc:mysql://localhost/mydatabase";
      Connection con = DriverManager.getConnection(mysqlUrl, "root", "password");
      System.out.println("Connection established......");
      //Creating a Statement object
      Statement stmt = con.createStatement();
      //Retrieving the data
      ResultSet rs = stmt.executeQuery("select * from MyPlayers");
      //Moving the cursor to the last row
      rs.last();
      System.out.println("Table contains "+rs.getRow()+" rows");
   }
}

Output

Connection established......
Table contains 8 rows
raja
Published on 16-May-2019 12:23:02
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