最好使用基于 PLINQ 的高性能库,如 System.Data.SqlClient 和 AggregationFramework。以下是一个使用 PLINQ 和 System.Data.SqlClient 的代码示例:
using System.Linq;
using System.Data.SqlClient;
...
var connectionString = "Your Connection String"; // Replace with your connection string
var query = "SELECT CustomerID, COUNT(*) AS TotalOrders FROM Orders GROUP BY CustomerID";
using (var conn = new SqlConnection(connectionString))
{
conn.Open();
var command = new SqlCommand(query, conn);
var result = command.ExecuteReader()
.Cast()
.AsParallel()
.ToLookup(
r => r.GetString(0), // Group by CustomerID
r => r.GetInt32(1)); // Get count of orders
foreach (var item in result)
{
Console.WriteLine($"CustomerID: {item.Key}, Total Orders: {item.Sum()}");
}
}