JDBC連線資料庫(查詢)的步驟
簡單的應用例子
先匯入jar包
程式碼:
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class Firstjdbc {
public static void main(String[] args) throws ClassNotFoundException, SQLException {
//1)註冊載入驅動
Class.forName("com.mysql.jdbc.Driver");
//DriverManager.registerDriver(new com.mysql.jdbc.Driver());
//2)獲得連線
String url = "jdbc:mysql://localhost:3307/mydb" ;//mydb為資料庫的名稱
String user = "root"; //資料庫的登入名
String password = "123456"; //資料庫的登入密碼
Connection conn = DriverManager.getConnection(url, user, password);
//3)建立語句物件
Statement st = conn.createStatement();
//4)執行sql獲得結果
String sql = "select * from emp "; //emp為要查詢的表名
ResultSet rs= st.executeQuery(sql);
//5)處理結果
while(rs.next()){
System.out.print(rs.getObject(1)+"\t");
System.out.print(rs.getObject(2)+"\t");
System.out.print(rs.getObject(3)+"\t");
System.out.print(rs.getObject(4)+"\t");
System.out.print(rs.getObject(5)+"\t");
System.out.print(rs.getObject(6)+"\t"); //共輸出要顯示的欄位名資訊
}
//6)關閉資源
rs.close();
st.close();
conn.close();
}
}