使用反射C＃的常見CRUD函數

Question

這是我的情況，我必須創建一個通用函數以將值插入MySQL數據庫。 到目前為止，我有下面的方法。 當另一個類中沒有復合類時，此代碼可以正常工作。 如果我們在實體中具有導航屬性，則此代碼將中斷，我被困在這里。

（ORM-由於其客戶要求，我們無法使用它）

public string create(object entity){
    var sql = new OdbcCommand();
        var d = new StringDictionary();
        var dd = new StringDictionary();
        try
        {
            var objectType = entity.GetType();
            var properties = objectType.GetProperties();
            var tableName = objectType.GetCustomAttributes(false).Select(x => (x as TableAttribute).Name).FirstOrDefault();
            foreach (var prop in properties)
            {
                if (prop.DeclaringType != typeof (BasicRequest)) // BasicRequest is base class
                {
                    if (
                        prop.GetCustomAttributes(false).Where(y=>y is ColumnAttribute).Select(x => (x as ColumnAttribute)).FirstOrDefault().IsPrimaryKey)
                    {
                        continue;
                    }
                    if (prop.PropertyType.IsGenericType) // here comes the problem
                    {
                        // the problem is if a class has List of its child 
                          objects then how to insert them since here parent 
                          is not yet inserted.
                    }
                    if (prop.GetCustomAttributes(false).Where(y => y is ColumnAttribute).Select(x => (x as ColumnAttribute)).FirstOrDefault().IsParent)
                    {
                         // same problem here also but this time this object is
                         parent object of the entity
                        /*parentObject = prop.GetValue(entity, null);
                        CreateNew(parentObject);
                        */

                        continue;
                    }
                    d[prop.GetCustomAttributes(false).Where(y => y is ColumnAttribute).Select(x => (x as ColumnAttribute).Name).FirstOrDefault()] = DBUtil.FixSQLString(Convert.ToString(prop.GetValue(entity, null)));
                }
                else
                {
                    continue;
                }
            }
            Connection coxn = ConnectionPool.GetInstance().GetCoxn(Constants.MyName,ConnectionPool.WriteServer,"db_name");
            sql.Connection = coxn.odbcConnection;
            sql.CommandType = CommandType.Text;
            sql.CommandText = DBUtil.CreateInsert(tableName, d);
            int affected = sql.ExecuteNonQuery();

            if (affected != 1)
            {
                ErrorMessage = "Insert Failed Unexpectedly";
                return "0";
            }
            return "1";

        }
        catch (Exception ex)
        {
            ErrorMessage = ex.Message;
            return "0";
        }
}

讓我們接受一個實體（這種設計不在我手中，此類已經存在，我無法更改此實體）

[Table(Name="person")]
public class Person
{
    [Column(Name="id",IsPrimaryKey=true)] // Column is my custom attribute
    public int Id{get;set;}
    [Column(Name="name",IsPrimaryKey=true)]
    public string Name{get;set;}
   // this is where i'm not able get it how do i insert
   // child class with the function i wrote above 
    [Column(IsChild=true)]
    public List<Contact> contact{get;set;} // Navigation property
    //Same problem with this property also 
    // how do i do insert for parent
    [Column(IsParent=true)]
    public User user{get;set;}

}

// i'll call that insert method as
Common c = new Common();
c.Create(Person p); // p will be passed as argument from controller

Answer 1

請允許我建議使用微型裝配，而不是手寫所有這些功能。

我建議使用Dapper或PetaPoco （您可以將其作為單個文件添加到應用程序中）。

Answer 2

看起來您正在嘗試創建自己的ORM實現。 這將非常復雜，絕對不值得為客戶項目付出努力。

您可以使用代碼生成工具從數據庫結構生成數據訪問層。 例如，CodeSmith http://www.codesmithtools.com/ 。