JDBCステートメントの例 – レコードのリストを選択する
次に、JDBCステートメントを使用してテーブルからレコード全体を選択し、ResultSetオブジェクトを介してすべてのレコードを表示する方法を示す例を示します。 selectクエリを発行するには、次のように `Statement.executeQuery`メソッドを呼び出します。
String selectTableSQL = "SELECT USER__ID, USERNAME from DBUSER"; Statement statement = dbConnection.createStatement(); ResultSet rs = statement.executeQuery(selectTableSQL); 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.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class JDBCStatementSelectExample { 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 { selectRecordsFromDbUserTable(); } catch (SQLException e) { System.out.println(e.getMessage()); } } private static void selectRecordsFromDbUserTable() throws SQLException { Connection dbConnection = null; Statement statement = null; String selectTableSQL = "SELECT USER__ID, USERNAME from DBUSER"; try { dbConnection = getDBConnection(); statement = dbConnection.createStatement(); System.out.println(selectTableSQL); //execute select SQL stetement ResultSet rs = statement.executeQuery(selectTableSQL); 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 (statement != null) { statement.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; } }