JDBC PreparedStatementを介してテーブルからレコードを選択し、ResultSetオブジェクトを介してレコードを表示する方法を示す例を次に示します。 selectクエリを発行するには、次のように `PreparedStatement.executeQuery（）`メソッドを呼び出します。
String selectSQL = "SELECT USER__ID, USERNAME FROM DBUSER WHERE USER__ID = ?";
PreparedStatement preparedStatement = dbConnection.prepareStatement(selectSQL);
preparedStatement.setInt(1, 1001);
ResultSet rs = preparedStatement.executeQuery(selectSQL );
while (rs.next()) {
String userid = rs.getString("USER__ID");
String username = rs.getString("USERNAME");
}
完全な例…
package com.mkyong.jdbc;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class JDBCPreparedStatementSelectExample {
private static final String DB__DRIVER = "oracle.jdbc.driver.OracleDriver";
private static final String DB__CONNECTION = "jdbc:oracle:thin:@localhost:1521:MKYONG";
private static final String DB__USER = "user";
private static final String DB__PASSWORD = "password";
public static void main(String[]argv) {
try {
selectRecordsFromTable();
} catch (SQLException e) {
System.out.println(e.getMessage());
}
}
private static void selectRecordsFromTable() throws SQLException {
Connection dbConnection = null;
PreparedStatement preparedStatement = null;
String selectSQL = "SELECT USER__ID, USERNAME FROM DBUSER WHERE USER__ID = ?";
try {
dbConnection = getDBConnection();
preparedStatement = dbConnection.prepareStatement(selectSQL);
preparedStatement.setInt(1, 1001);
//execute select SQL stetement
ResultSet rs = preparedStatement.executeQuery();
while (rs.next()) {
String userid = rs.getString("USER__ID");
String username = rs.getString("USERNAME");
System.out.println("userid : " + userid);
System.out.println("username : " + username);
}
} catch (SQLException e) {
System.out.println(e.getMessage());
} finally {
if (preparedStatement != null) {
preparedStatement.close();
}
if (dbConnection != null) {
dbConnection.close();
}
}
}
private static Connection getDBConnection() {
Connection dbConnection = null;
try {
Class.forName(DB__DRIVER);
} catch (ClassNotFoundException e) {
System.out.println(e.getMessage());
}
try {
dbConnection = DriverManager.getConnection(
DB__CONNECTION, DB__USER,DB__PASSWORD);
return dbConnection;
} catch (SQLException e) {
System.out.println(e.getMessage());
}
return dbConnection;
}
}
