写List<；对象>；到数据库

本文关键字：数据库 gt 对象 lt List | 更新日期: 2023-09-27 17:59:14

请解释如何使WriteToBase()方法更快，或者如何在不调用每个insert的情况下进行大容量插入。

    class MyClass
    {
        public int a;
        public int b;
        public int c;
    }
    void main()
    {
        List<MyClass> mc = new List<MyClass>();
        mc.Add(new MyClass()); //example
        mc.Add(new MyClass());
        WriteToBase(mc);
    }
    void WriteToBase(List<MyClass> mc)
    {
        //Create Connection
        string sqlIns = "INSERT INTO table (name, information, other) VALUES (@name,           @information, @other)";
        SqlCommand cmdIns = new SqlCommand(sqlIns, Connection);
        for (int i = 0; i < mc.Count; i++)
        {
            cmdIns.Parameters.Add("@name", mc[i].a);
            cmdIns.Parameters.Add("@information", mc[i].b);
            cmdIns.Parameters.Add("@other", mc[i].c);
            cmdIns.ExecuteNonQuery();
        }
    }

有什么想法吗？

写List<；对象>；到数据库

您当前正在多次访问数据库。所有插入应该只有1次命中。

试试这个代码：

void WriteToBase(List<MyClass> mc)
{
  //Create Connection
  using (TransactionScope scope = new TransactionScope())
  {
    string sqlIns = "INSERT INTO table (name, information, other) 
                     VALUES (@name, @information, @other)";
    SqlCommand cmdIns = new SqlCommand(sqlIns, Connection);
    for(int i=0;i<mc.Count;i++)
    {
      cmdIns.Parameters.Add("@name", mc[i].a);
      cmdIns.Parameters.Add("@information", mc[i].b);
      cmdIns.Parameters.Add("@other", mc[i].c);
      cmdIns.ExecuteNonQuery();
    }
    scope.Complete();    
  }
}

使用SqlBulkCopy。它使您能够高效地使用来自另一个源的数据大容量加载SQL Server表。

private static void WriteToBase(IEnumerable<MyClass> myClasses)
    {
        var dataTable = new DataTable();
        dataTable.Columns.Add("name", typeof(string));
        dataTable.Columns.Add("information", typeof(string));
        dataTable.Columns.Add("other", typeof(string));
        foreach (var myClass in myClasses)
        {
            var row = dataTable.NewRow();
            row["name"] = myClass.name;
            row["information"] = myClass.information;
            row["other"] = myClass.other;
            dataTable.Rows.Add(row);
        }
        using var connection = new SqlConnection(Constants.YourConnectionString);
        connection.Open();
        using var bulk = new SqlBulkCopy(connection) {DestinationTableName = "table" };
        bulk.WriteToServer(dataTable);
    }

void WriteToBase(List<MyClass> mc)
{
  //Create Connection
  using (TransactionScope scope = new TransactionScope())
  {
    string sqlIns = "INSERT INTO table (name, information, other) 
                     VALUES (@name, @information, @other)";
    SqlCommand cmdIns = new SqlCommand(sqlIns, Connection);
    for(int i=0;i<mc.Count;i++)
    {
      cmdIns.Parameters.AddWithValue("@name", mc[i].a);
      cmdIns.Parameters.AddWithValue("@information", mc[i].b);
      cmdIns.Parameters.AddWithValue("@other", mc[i].c);
      cmdIns.ExecuteNonQuery();
      cmdIns.Parameters.Clear();
    }
    scope.Complete();    
  }
}
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