
Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Java ResultSet isBeforeFirst Method with Example
When we execute certain SQL queries (SELECT query in general) they return tabular data.
The java.sql.ResultSet interface represents such tabular data returned by the SQL statements.
i.e. the ResultSet object holds the tabular data returned by the methods that execute the statements which quires the database (executeQuery() method of the Statement interface in general).
The ResultSet object has a cursor/pointer which points to the current row. Initially this cursor is positioned before first row.
The isBeforeFirst() method of the ResultSet interface is used to determine whether the cursor is at the default position of the ResultSet.
rs.isBeforeFirst();
This method returns an boolean this value is true, if the cursor is at the default position of the ResultSet else, it returns false.
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 establishes connection with the database, retrieves the contents of the table MyPlayers into a ResultSet object and, determines whether the cursor is at the default position of the ResultSet.
Example
import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class ResultSet_isBeforeFirst { public static void main(String args[]) throws SQLException { //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 the Statement Statement stmt = con.createStatement(); //Query to retrieve records String query = "Select * from MyPlayers"; //Executing the query ResultSet rs = stmt.executeQuery(query); //Verifying whether the cursor is at the end of the ResultSet (after last). boolean bool= rs.isBeforeFirst(); if(bool) { System.out.println("Cursor of the current ResultSet object is at the default poition of the ResultSet"); } else { System.out.println("Cursor of the current ResultSet object is not at the default poition of the ResultSet"); } rs.beforeFirst(); if(rs.isBeforeFirst()) { System.out.println("Cursor of the current ResultSet object is at the default poition of the ResultSet"); } else { System.out.println("Cursor of the current ResultSet object is not at the default poition of the ResultSet"); } } }
Output
Connection established...... Cursor of the current ResultSet object is at the default poition of the ResultSet Cursor of the current ResultSet object is at the default poition of the ResultSet