java连接sqlserver怎么实现增删改查

```java

import java.sql.*;

public class Main {

public static void main(String[] args) {

String url = "jdbc:sqlserver://localhost:1433;databaseName=mydatabase";

String username = "username";

String password = "password";

try {

// 连接数据库

Connection connection = DriverManager.getConnection(url, username, password);

// 执行查询操作

Statement statement = connection.createStatement();

ResultSet resultSet = statement.executeQuery("SELECT * FROM mytable");

while(resultSet.next()){

String column1 = resultSet.getString("column1");

String column2 = resultSet.getString("column2");

System.out.println("column1: " + column1 + ", column2: " + column2);

}

// 执行插入操作

statement.executeUpdate("INSERT INTO mytable (column1, column2) VALUES ('value1', 'value2')");

// 执行更新操作

statement.executeUpdate("UPDATE mytable SET column1 = 'updated value1' WHERE column2 = 'value2'");

// 执行删除操作

statement.executeUpdate("DELETE FROM mytable WHERE column1 = 'value1'");

connection.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

}

```

需要注意的是，在上述代码中，需要将`url`、`username`和`password`替换为你自己数据库的连接信息。同时，需要确保已经在项目中引入了SQL Server的JDBC驱动。