포스코DX X 비트교육센터 6기 - SQL | DBMS 설계 | JDBC

<project xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.poscodx</groupId>
	<artifactId>jdbc-practices</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	
	<dependencies>
		<dependency>
		    <groupId>org.mariadb.jdbc</groupId>
		    <artifactId>mariadb-java-client</artifactId>
		    <version>3.0.8</version>
		</dependency>
	</dependencies>
	
	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.build.outputEncoding>UTF-8</project.build.outputEncoding>
		<maven.compiler.source>17</maven.compiler.source>
		<maven.compiler.target>17</maven.compiler.target>
	</properties>
	
	<build>
		<finalName>jdbc-practices</finalName>
	</build>		
</project>

package test;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class TestConnection {
	public static void main(String[] args) {

		Connection conn = null;
		try {
			// 1. JDBC Driver Class 로딩
			Class.forName("org.mariadb.jdbc.Driver");

			// 2. 연결하기
			String url = "jdbc:mariadb://192.168.0.178:3307/webdb?charset=utf8";
			conn = DriverManager.getConnection(url, "webdb", "webdb");

			System.out.println("연결성공!");

		} catch (ClassNotFoundException e) {
			System.out.println("드라이버 로딩 실패:" + e);

		} catch (SQLException e) {
			System.out.println("error:" + e);
		} finally {

			try {
				if (conn != null) {
					conn.close();
				}
			} catch (SQLException e) {
				e.printStackTrace();
			}

		}

	}
}

package test;

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

public class SelectTest01 {
	public static void main(String[] args) {
		searchEployees("ko");

	}

	public static void searchEployees(String keyword) {
		Connection conn = null;
		Statement stmt = null;
		ResultSet rs = null;

		try {
			// 1. JDBC Driver Class 로딩
			Class.forName("org.mariadb.jdbc.Driver");

			// 2. 연결하기
			String url = "jdbc:mariadb://192.168.0.178:3307/employees?charset=utf8";
			conn = DriverManager.getConnection(url, "hr", "hr");

			// 3. Statement 객체 생성
			stmt = conn.createStatement();

			// 4. SQL 실행 -- 띄어쓰기 조심, 뒤에 세미콜론(;) 안 붙이도록 조심.
			String sql = "select emp_no, first_name, last_name" + " from employees" + " where first_name like '%"
					+ keyword + "%'" + " and last_name like '%" + keyword + "%'";

			rs = stmt.executeQuery(sql);

			// 5. 결과 처리
			while (rs.next()) {
				Long empNo = rs.getLong(1);
				String firstName = rs.getString(2);
				String lastName = rs.getString(3);

				System.out.println(empNo + ":" + firstName + ":" + lastName);
			}

		} catch (ClassNotFoundException e) {
			System.out.println("드라이버 로딩 실패:" + e);

		} catch (SQLException e) {
			System.out.println("error:" + e);
		} finally {

			try {
				// 6. 자원정리
				if(rs!=null) {
					rs.close();
				}
				if(stmt!=null) {
					stmt.close();
				}
				if (conn != null) {
					conn.close();
				}
			} catch (SQLException e) {
				e.printStackTrace();
			}

		}
	}
}