The PreparedStatement interface is a subinterface of Statement. It is used to execute a parameterized query.
A SQL statement is precompiled and stored in a PreparedStatement object. This object can then be used to efficiently execute this statement multiple times.
JDBC PreparedStatement Select Records Example
Here we have a users table in a database and we will query a list of users from the database table by id.
Steps to process select SQL statement with JDBC:
- Establishing a connection.
- Create a statement.
- Execute the query.
- Using try-with-resources Statements to Automatically Close JDBC Resources
package com.javaguides.jdbc.preparestatement.examples;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
/**
* Select PreparedStatement JDBC Example
*
* @author Ramesh Fadatare
*
*/
public class SelectPStatementExample {
private static final String QUERY = "select id,name,email,country,password from Users where id =?";
public static void main(String[] args) {
// using try-with-resources to avoid closing resources (boiler plate code)
// Step 1: Establishing a Connection
try (Connection connection = DriverManager
.getConnection("jdbc:mysql://localhost:3306/mysql_database?useSSL=false", "root", "root");
// Step 2:Create a statement using connection object
PreparedStatement preparedStatement = connection.prepareStatement(QUERY);) {
preparedStatement.setInt(1, 1);
System.out.println(preparedStatement);
// Step 3: Execute the query or update query
ResultSet rs = preparedStatement.executeQuery();
// Step 4: Process the ResultSet object.
while (rs.next()) {
int id = rs.getInt("id");
String name = rs.getString("name");
String email = rs.getString("email");
String country = rs.getString("country");
String password = rs.getString("password");
System.out.println(id + "," + name + "," + email + "," + country + "," + password);
}
} catch (SQLException e) {
printSQLException(e);
}
// Step 4: try-with-resource statement will auto close the connection.
}
public static void printSQLException(SQLException ex) {
for (Throwable e: ex) {
if (e instanceof SQLException) {
e.printStackTrace(System.err);
System.err.println("SQLState: " + ((SQLException) e).getSQLState());
System.err.println("Error Code: " + ((SQLException) e).getErrorCode());
System.err.println("Message: " + e.getMessage());
Throwable t = ex.getCause();
while (t != null) {
System.out.println("Cause: " + t);
t = t.getCause();
}
}
}
}
}
Output:
1,Ram,tony@gmail.com,US,secret
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