import java.sql.*;

public class ConnDatabase {
	private static final String DBDRIVER="com.microsoft.sqlserver.jdbc.SQLServerDriver";
	private static final String DBURL="jdbc:sqlserver://localhost:1433;DatabaseName=School1";
	private static final String DBUSER="sa";
	private static final String DBPWD="sa";                            
	//Refresh
	public static void Query(ResultSet rs) throws Exception{
		System.out.println("No\tName\tAge\tSex");//学号、姓名、年龄、性别
		while(rs.next()){
			String no = rs.getString("No");
			String name = rs.getString("Name");
			int age = rs.getInt("Age");
			String sex = rs.getString("Sex");
			System.out.println(no+"\t"+name+"\t"+age+"\t"+sex);
		}
	}
	public static void main(String[] args) throws Exception{
		Class.forName(DBDRIVER);//加载驱动
		Connection conn = DriverManager.getConnection(DBURL,DBUSER,DBPWD);//连接数据库
		Statement stmt = conn.createStatement();//数据库操作
		
		//建表
		stmt.execute("CREATE TABLE Stu5"+"(No varchar(20) PRIMARY KEY,"+"Name varchar(10),"+"Age int,"+"Sex varchar(2))");
		String sqlResult = "select * from Stu5";
		ResultSet rs = stmt.executeQuery(sqlResult);
		Query(rs);
		
		//Add
		stmt.executeUpdate("INSERT INTO Stu5(No,Name,Age,Sex)"+"VALUES('134','陈艳',19,'女')");
		rs = stmt.executeQuery(sqlResult);
		Query(rs);
		
		//Change
		stmt.executeUpdate("UPDATE Stu5 SET Age = 20 WHERE Name = '陈艳'");
		rs = stmt.executeQuery(sqlResult);
		Query(rs);
		
		//Delete
		stmt.executeUpdate("DELETE FROM Stu5 WHERE Name='陈艳'");
		rs = stmt.executeQuery(sqlResult);
		Query(rs);
		
		rs.close();
		stmt.close();
		conn.close();
	}
}

PS：private static final String DBURL="jdbc:sqlserver://localhost:1433;DatabaseName=School1"；这行代码有两个地方需要注意：

1、DBURL需要根据实际情况更改。

2、DatabaseName=School1，之前我是写的DatabaseName=‘School1’，结果错了。这个小错误，我花了好久时间找出来并改正，希望大家注意，不要和我犯同样的错误。