Friday, December 4, 2009

Check if there are some records in ResultSet return from MySQL Database using Java

import java.sql.*;
import java.util.*;
import java.sql.DriverManager;
// return true if some records satisfy the condition, otherwase, false.
public Boolean IsExifPhotoIdTimeLongitudeLatitude( String photoId, String time, String longitude, String latitude ){
	Connection con = null;
	String url = "";
	String driver = "";
	Statement stmt = null;
	String query = "";
	// your database table name
	String targetSheet = "db_table_name";
	ResultSet result = null;
	Boolean hasRecord = false;
	// your query
	query = "SELECT * FROM `"+ targetSheet +"` WHERE photoId='" + photoId + "' AND time='" + time + "' AND longitude='" + longitude + "' AND latitude='" + latitude + "'";
	try{
		// connect to mysql database
		
		url = "jdbc:mysql://127.0.0.1:3306/database_name";
		driver = "com.mysql.jdbc.Driver";
		p = new Properties();
		Class.forName(driver).newInstance();
		con = DriverManager.getConnection(url, "user_name", "pass_word");
		
		// create statement
		stmt = con.createStatement();
		
		// execute your query
		result = stmt.executeQuery(query);
			
		// result.first() will return false if there is no record
		// Important: executeQuery never return null
		
		if( result.first() ){
			hasRecord = true;
		}
	}
	catch( Exception e ) {
		e.printStackTrace();
	}
	finally {
	}
	return hasRecord;
}

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