帮我写一个基础的C#DbHerper类
时间: 2024-09-24 19:13:52 浏览: 20
在C#中,DbHelper是一个常见的数据库操作工具类,用于简化数据库访问。下面是一个基本的示例,这个DbHelper类包含了连接数据库、查询数据和关闭连接等常用功能:
```csharp
using System.Data.SqlClient;
public class DBHelper
{
private string connectionString; // 数据库连接字符串
public DBHelper(string dbConnection)
{
connectionString = dbConnection;
}
// 连接到数据库
public void OpenConnection()
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
try
{
connection.Open();
Console.WriteLine("Connected to the database.");
}
catch (Exception ex)
{
Console.WriteLine($"Error connecting to database: {ex.Message}");
}
}
}
// 执行SQL查询并返回DataTable
public DataTable ExecuteQuery(string sqlCommand)
{
DataTable dataTable = new DataTable();
using (SqlCommand command = new SqlCommand(sqlCommand, connection))
{
SqlDataAdapter adapter = new SqlDataAdapter(command);
adapter.Fill(dataTable);
}
return dataTable;
}
// 关闭数据库连接
public void CloseConnection()
{
if (connection.State == ConnectionState.Open)
{
connection.Close();
Console.WriteLine("Database connection closed.");
}
else
{
Console.WriteLine("Connection is already closed.");
}
}
}
```
在这个例子中,你需要替换`connectionString`变量为你实际的数据库连接字符串。使用时先创建一个DbHelper实例,然后调用`OpenConnection()`打开连接,执行SQL命令(通过`ExecuteQuery`方法),最后记得关闭连接。