在窗体加载时设置行源(Access、SQL)

using System.Data.OleDb;

string connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\path\\to\\database.accdb";

using (OleDbConnection connection = new OleDbConnection(connectionString))
{
    connection.Open();
    // 进行后续操作
}

string query = "SELECT * FROM TableName";

using (OleDbCommand command = new OleDbCommand(query, connection))
{
    using (OleDbDataReader reader = command.ExecuteReader())
    {
        while (reader.Read())
        {
            // 处理每一行数据
        }
    }
}

using System.Data.SqlClient;

string connectionString = "Data Source=ServerName;Initial Catalog=DatabaseName;User ID=Username;Password=Password";

using (SqlConnection connection = new SqlConnection(connectionString))
{
    connection.Open();
    // 进行后续操作
}

string query = "SELECT * FROM TableName";

using (SqlCommand command = new SqlCommand(query, connection))
{
    using (SqlDataReader reader = command.ExecuteReader())
    {
        while (reader.Read())
        {
            // 处理每一行数据
        }
    }
}