Java में MySQL PreparedStatement का WHERE क्लॉज के साथ सही उपयोग

PreparedStatement सिंटैक्स

String query = "select yourColumnName from yourTableName where name = ?";
PreparedStatement ps = (PreparedStatement) con.prepareStatement(query);
ps.setString(columnIndex, yourValue);

टेबल और डेटा

mysql> create table demo37 (id int not null auto_increment primary key, name varchar(200));
mysql> insert into demo37(name) values('John'), ('Bob'), ('John'), ('Chris'), ('David'), ('John'), ('Mike');

पूर्ण Java कोड उदाहरण

import java.sql.*;
public class PrepareStatementDemo {
    public static void main(String[] args) {
        Connection con = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            con = DriverManager.getConnection("jdbc:mysql://localhost:3306/sampledatabase", "root", "123456");
            String query = "select name from demo37 where name = ?";
            PreparedStatement ps = (PreparedStatement) con.prepareStatement(query);
            ps.setString(1, "John");
            ResultSet rs = ps.executeQuery();
            while (rs.next()) {
                System.out.println(rs.getString(1));
            }
        } catch (Exception e) { e.printStackTrace(); }
    }
}

आउटपुट

John
John
John

लाभ: SQL इंजेक्शन रोकथाम, प्रदर्शन (प्लान कैशिंग), कोड पठनीयता।