jdbc driver

접속하고 쿼리 준비, 쿼리 날리고 결과

데이터 꺼내고 처리하는 방식

1) connection

2) statement - 요청을 위한 쿼리 명령어

3) resultset - 개수만 알려주느거 select이면 resultset 나머지는 실행이 안됨!!

4) 끝내기

 

db경로 넣기

프로젝트에서 오른쪽클릭->build path->configure~~ -> libraries->add external jars...

 

import되면 완성~

import oracle.jdbc.driver.OracleDriver;

public class DBExample {
	public static void main(String[] args) {
		OracleDriver
	}
}

 

import한거 그대로 넣기

Class.forName("oracle.jdbc.driver.OracleDriver");

트라이캐치

public class DBExample {
	public static void main(String[] args) {
//		OracleDriver
		try {
			Class.forName("oracle.jdbc.driver.OracleDriver");
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}
}

 

DriverManager.getConnection("jdbc:oracle:thin:@192.168.20.59:1521:xe","java" , "oracle");

import java.sql.DriverManager;
import oracle.jdbc.driver.OracleDriver;

public class DBExample {
	public static void main(String[] args) {
//		OracleDriver
		try {
			Class.forName("oracle.jdbc.driver.OracleDriver");
			DriverManager.getConnection("jdbc:oracle:thin:@192.168.20.59:1521:xe","java" , "oracle");
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

 

어사인

Connection connection = DriverManager.getConnection("jdbc:oracle:thin:@192.168.20.59:1521:xe","java" , "oracle");

package chapter19;

import java.sql.Connection;
import java.sql.DriverManager;
import oracle.jdbc.driver.OracleDriver;

public class DBExample {
	public static void main(String[] args) {
//		OracleDriver
		try {
			Class.forName("oracle.jdbc.driver.OracleDriver");
			Connection connection = DriverManager.getConnection("jdbc:oracle:thin:@192.168.20.59:1521:xe","java" , "oracle");
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

statement

Statement statement = connection.createStatement();

package chapter19;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;

import oracle.jdbc.driver.OracleDriver;

public class DBExample {
	public static void main(String[] args) {
//		OracleDriver
		try {
			Class.forName("oracle.jdbc.driver.OracleDriver");
			Connection connection = DriverManager.getConnection("jdbc:oracle:thin:@192.168.20.59:1521:xe","java" , "oracle");
			Statement statement = connection.createStatement();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

 

쿼리문 작성

resultSet에 전체 들어감

			ResultSet resultSet = statement.executeQuery("select * from employees");

package chapter19;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import oracle.jdbc.driver.OracleDriver;

public class DBExample {
	public static void main(String[] args) {
//		OracleDriver
		try {
			Class.forName("oracle.jdbc.driver.OracleDriver");
			Connection connection = DriverManager.getConnection("jdbc:oracle:thin:@192.168.20.59:1521:xe","java" , "oracle");
			Statement statement = connection.createStatement();
			ResultSet resultSet = statement.executeQuery("select * from employees");
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

 

출력

목록형태이므로 반복문을 돌려줌

			while (resultSet.next()) {
				String empName = resultSet.getString("emp_name");
				String email = resultSet.getString("email");
				System.out.println(empName + ": " + email);
			}

package chapter19;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import oracle.jdbc.driver.OracleDriver;

public class DBExample {
	public static void main(String[] args) {
//		OracleDriver
		try {
			Class.forName("oracle.jdbc.driver.OracleDriver");
			Connection connection = DriverManager.getConnection("jdbc:oracle:thin:@192.168.20.59:1521:xe", "java",
					"oracle");
			Statement statement = connection.createStatement();
			ResultSet resultSet = statement.executeQuery("select * from employees");
			while (resultSet.next()) {
				String empName = resultSet.getString("emp_name");
				String email = resultSet.getString("email");
				System.out.println(empName + ": " + email);
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

 

자원 닫아

			resultSet.close();
			statement.close();
			connection.close();

package chapter19;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import oracle.jdbc.driver.OracleDriver;

public class DBExample {
	public static void main(String[] args) {
//		OracleDriver
		try {
			Class.forName("oracle.jdbc.driver.OracleDriver");
			Connection connection = DriverManager.getConnection("jdbc:oracle:thin:@192.168.20.59:1521:xe", "java",
					"oracle");
			Statement statement = connection.createStatement();
			ResultSet resultSet = statement.executeQuery("select * from employees");
			while (resultSet.next()) {
				String empName = resultSet.getString("emp_name");
				String email = resultSet.getString("email");
				System.out.println(empName + ": " + email);
			}
			resultSet.close();
			statement.close();
			connection.close();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}