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■ 1
package javapkg1;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class Connect100 {
public static void main(String[] args) throws ClassNotFoundException, SQLException {
// 자바 - DB 연동 : JDBC
// 연동을 위해 ojdbc8.jar가 필요.
// 프로젝트-마우스우클릭 - build path - configure build path
// - library 탭 - classPath - add external jar
// ojdbc8.jar를 선택한 후 apply and close
// 결과로 referenced libraries 안에서 ojdbc8.jar 파일 확인
// 이 방법은 프로젝트마다 jar 파일을 넣어야 한다.
// (즉, jar 파일을 jdk 안에 넣을 수도 있다.)
// DB와 접속해보자
Connection con = null; // 접속객체
// 드라이버 메모리 로딩
// 클래스명.스태틱메소드()
Class.forName("oracle.jdbc.driver.OracleDriver");
// ㄴ ojdbc8.jar 안에 oracle.jdbc.driver 패키지 안에
// ㄴ OracleDriver.class를 메모리에 로딩
// url 사용하여 접속
// 클래스명.스태틱메소드()
con = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:" // 내 자신한테 접속
+ "1521:xe", "hr", "hr");
System.out.println("접속성공!");
}
}
■ 2
package javapkg1;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;
public class Connect101 {
public static void main(String[] args) throws ClassNotFoundException, SQLException {
Connection con1 = null; // 접속객체
Class.forName("oracle.jdbc.driver.OracleDriver");
con1 = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:" // 내 자신한테 접속
+ "1521:xe", "hr", "hr");
System.out.println("접속성공!");
System.out.println("이제 사원명단 전체 검색");
Scanner sc1 = new Scanner(System.in);
System.out.print("검색할 사원의 이름은 : ");
String irum = sc1.next();
String sql2 = "select * from employees"
+ " where first_name = '" + irum + "'"; // 여기는 그냥 java 문장
// 그러므로 java 문장이 sql 문장이 되려면
Statement st2 = con1.createStatement(); // import java.sql...
ResultSet rs2 = st2.executeQuery(sql2); // executeQuery : 조회를 해라.
// rs2 가 가리키는 종이박스에 실행결과가 다 들어간다.
while(rs2.next()) {
int id = rs2.getInt("employee_id"); // 컬럼명, 순번, alias
// rs2.getInt(1); 도 가능
String fname = rs2.getString("first_name");
int salary = rs2.getInt("salary"); // rs2.getInt(18); 도 가능
int d_id = rs2.getInt("department_id");
String email = rs2.getString("email");
String l_name = rs2.getString("last_name");
String h_date = rs2.getString("hire_date");
String h2_date = h_date.substring(0, 10); // 시간을 제거하기 위해
// 나는 몇번째 row에서 진행중인지 알고 싶다. 일련번호 찍기
System.out.println(rs2.getRow() + "\t" + id + "\t"
+ h2_date + "\t" + fname + "\t" + salary + "\t"
+ d_id + "\t" + email + "\t" + l_name);
// 2006-05-23 00:00:00 => db에서 보면 06/05/23
}
con1.close();
System.out.println("접속끝");
}
}
■ 3
package javapkg3;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;
public class Connection104 {
public static void main(String[] args) throws SQLException, ClassNotFoundException {
Connection con1 = null; // 접속객체
Class.forName("oracle.jdbc.driver.OracleDriver");
con1 = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:" // 내 자신한테 접속
+ "1521:xe", "hr", "hr");
System.out.println("접속성공!");
System.out.println("이제 사원명단 전체 검색");
Scanner sc1 = new Scanner(System.in);
System.out.println("검색 급여 기준 : ");
int sal2 = sc1.nextInt();
String sql2 = "select first_name 이름, salary 봉급"
+ " from employees"
+ " where salary >= ?";
// ?로 대체
PreparedStatement ps2 = con1.prepareStatement(sql2); // sql2 o
// 클래스 // 접속객체.메소드()
// ?를 채워야 한다.
ps2.setInt(1, sal2);
ResultSet rs2 = ps2.executeQuery(); // sql2 x
while(rs2.next()) {
String fname = rs2.getString("이름"); // alias를 사용할 거면 써먹어야 한다.
// 만약 써놓고 사용하지 않으면 에러
int salary = rs2.getInt("봉급");
System.out.println(rs2.getRow() + "\t" + fname + "\t" + salary);
}
con1.close();
System.out.println("접속끝");
}
}
■ 4 - GUI 연동
package javapkg7;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
import java.awt.Color;
import java.awt.Font;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Scanner;
public class ChangeNameGui extends JFrame {
private JPanel contentPane;
private JTextField textField;
private JTextField textField_1;
private JTextField txtDisplay;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
ChangeNameGui frame = new ChangeNameGui();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public ChangeNameGui() {
setForeground(Color.GREEN);
setTitle("\uB0B4\uAC00\uB9CC\uB4E0 \uC5C5\uB370\uC774\uD2B8 GUI");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 919, 395);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);
JLabel lblNewLabel = new JLabel("\uBCC0\uACBD\uD560\uC774\uB984");
lblNewLabel.setForeground(Color.BLUE);
lblNewLabel.setFont(new Font("맑은 고딕", Font.BOLD, 15));
lblNewLabel.setBounds(48, 40, 160, 29);
contentPane.add(lblNewLabel);
textField = new JTextField();
textField.setBackground(Color.YELLOW);
textField.setForeground(Color.RED);
textField.setFont(new Font("맑은 고딕", Font.BOLD, 15));
textField.setBounds(246, 35, 253, 34);
contentPane.add(textField);
textField.setColumns(10);
JLabel lblNewLabel_1 = new JLabel("\uBCC0\uACBD\uB420\uC774\uB984");
lblNewLabel_1.setForeground(Color.BLUE);
lblNewLabel_1.setFont(new Font("맑은 고딕", Font.BOLD, 15));
lblNewLabel_1.setBounds(48, 82, 160, 42);
contentPane.add(lblNewLabel_1);
textField_1 = new JTextField();
textField_1.setForeground(Color.RED);
textField_1.setBackground(Color.YELLOW);
textField_1.setFont(new Font("맑은 고딕", Font.BOLD, 15));
textField_1.setBounds(246, 79, 253, 34);
contentPane.add(textField_1);
textField_1.setColumns(10);
JButton btnNewButton = new JButton("\uC774\uB984 \uC5C5\uB370\uC774\uD2B8");
btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
//여기다가 도스소스 복사해서 붙여
Connection con1=null;
try {
Class.forName ("oracle.jdbc.driver.OracleDriver");
} catch (ClassNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
con1 = DriverManager.getConnection //db접속
("jdbc:oracle:thin:@127.0.0.1:"
+ "1521:xe", "hr","hr");
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
//("jdbc:oracle:thin:@127.0.0.1:1521:xe", "hr","hr");
System.out.println("접속했다고 전해라");
/*create table jdbc_tab3(
sawon_id number(10),
sawon_name varchar2(20),
sawon_sal number(10),
sawon_jik varchar2(20)
);
insert into jdbc_tab3
values (1,'홍길동',3700000,'대리');
*/
String sql2 =
"update jdbc_tab3 " +
"set sawon_name= ? " +
"where sawon_name = ? ";
PreparedStatement pst1=null;////////////////
try {
pst1 = con1.prepareStatement(sql2);
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
/* Scanner sc1=new Scanner(System.in);
System.out.print("변경할이름: ");
String hal_name=sc1.next();
System.out.print("변경될이름: ");
String deul_name=sc1.next();*/
try {
pst1.setString(1, textField_1.getText());//텍스트필드에 있는 변경될 이름
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
//pst1.setString(1, deul_name);
try {
pst1.setString(2,textField.getText()) ;//텍스트필드에 있는 변경할 이름
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
//pst1.setString(2, hal_name);
int rowcnt1=0;////////////////
try {
rowcnt1 = pst1.executeUpdate();
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}//////
if(rowcnt1 >=1) {
txtDisplay.setText("update ok !!!");
System.out.println(rowcnt1+"행 update");//update 행 갯수
}
else {
txtDisplay.setText("update error !!!");
System.out.println("update error");
}
try {
con1.close();
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}//////////////////////
System.out.println("접속끝"); //////////////
}
});
btnNewButton.setBackground(Color.GREEN);
btnNewButton.setForeground(Color.MAGENTA);
btnNewButton.setFont(new Font("맑은 고딕", Font.BOLD, 15));
btnNewButton.setBounds(270, 199, 160, 42);
contentPane.add(btnNewButton);
txtDisplay = new JTextField();
txtDisplay.setFont(new Font("굴림", Font.BOLD, 18));
txtDisplay.setBounds(114, 266, 462, 51);
contentPane.add(txtDisplay);
txtDisplay.setColumns(10);
}
}728x90
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