通過泛型插入（更新）實體數據

經過長時間的。net開發，發現每次操作數據這塊，很繁瑣，要麼是直接拼接sql語句，要麼是利用實體類，但是還是需要拼接sql語句，如何找到一個能減少拼接sql語句的並且還能用到實體類數據的方法呢，我在一直摸索。於是得出了一下方法：、

 

 

現舉例示範代碼如下，當然我覺得還可以改進（比如重複的地方還可以寫成公共方法進行調用）。

/// <summary>
/// 通過泛型插入數據
/// </summary>
/// <typeparam name="T">類名稱</typeparam>
/// <param name="obj">類對象,如果要插入空值，請使用@NULL</param>
/// <returns>插入的新記錄ID</returns>
public static int Insert<T>(T obj)
{

      StringBuilder strSQL = new StringBuilder();

      strSQL = GetInsertSQL(obj);

      // 插入到數據庫中
      object result = SQLPlus.ExecuteScalar(CommandType.Text, strSQL, null);

      return Convert.IsDBNull(result) ? 0 : Convert.ToInt32(result);
}

/// <summary>
/// 通過泛型更新數據
/// </summary>
/// <typeparam name="T">類名稱</typeparam>
/// <param name="obj">類對象,如果要更新空值，請使用@NULL</param>
/// <returns>更新結果,大於0爲更新成功</returns>
public static int Update<T>(T obj)
{

     StringBuilder strSQL = new StringBuilder();
     strSQL = GetUpdateSQL(obj);

     if (String.IsNullOrEmpty(strSQL.ToString()))
     {
          return 0;
     }


     // 更新到數據庫中
     object result = SQLPlus.ExecuteNonQuery(CommandType.Text, strSQL, null);

     int returnValue = Convert.IsDBNull(result) ? 0 : Convert.ToInt32(result);

     return returnValue;

}

/// <summary>
/// 獲取實體的插入語句
/// </summary>
/// <typeparam name="T">泛型</typeparam>
/// <param name="obj">實體對象</param>
/// <returns>返回插入語句</returns>
public static StringBuilder GetInsertSQL<T>(T obj)
{

      string tableKey = GetPropertyValue(obj, BaseSet.PrimaryKey);
      string keyValue = GetPropertyValue(obj, tableKey);
      string tableName = GetPropertyValue(obj, BaseSet.TableName);

      Type t = obj.GetType();//獲得該類的Type

      StringBuilder strSQL = new StringBuilder();

      strSQL.Append("insert into " + tableName + "(");

      string fields = "";
      string values = "";

      //再用Type.GetProperties獲得PropertyInfo[]
      foreach (PropertyInfo pi in t.GetProperties())
      {

           object name = pi.Name;//用pi.GetValue獲得值

           // 替換Sql注入符
           string value1 = Convert.ToString(pi.GetValue(obj, null)).Replace("'", "''");

           //string dataType = pi.PropertyType.ToString().ToLower();

           string properName = name.ToString().ToLower();

           if (!string.IsNullOrEmpty(value1) && properName != tableKey.ToLower() && properName != BaseSet.PrimaryKey.ToLower() && properName != BaseSet.TableName.ToLower() && value1 != BaseSet.DateTimeLongNull && value1 != BaseSet.DateTimeShortNull)
           {
                // 判斷是否爲空
                if (value1 == BaseSet.NULL)
                {
                    value1 = "";
                }

                fields += Convert.ToString(name) + ",";
                values += "'" + value1 + "',";

           }

       }

       // 去掉最後一個,
       fields = fields.TrimEnd(',');
       values = values.TrimEnd(',');

       // 拼接Sql串
       strSQL.Append(fields);
       strSQL.Append(") values (");
       strSQL.Append(values);
       strSQL.Append(")");

       strSQL.Append(";SELECT @@IDENTITY;");

       return strSQL;
}

/// <summary>
/// 獲取實體的更新SQL串
/// </summary>
/// <typeparam name="T">泛型</typeparam>
/// <param name="obj">實體對象</param>
/// <returns>返回插入語句</returns>
private static StringBuilder GetUpdateSQL<T>(T obj)
{

     string tableKey = GetPropertyValue(obj, BaseSet.PrimaryKey);
     string keyValue = GetPropertyValue(obj, tableKey);
     string tableName = GetPropertyValue(obj, BaseSet.TableName);
     StringBuilder strSQL = new StringBuilder();

     if (string.IsNullOrEmpty(keyValue))
     {
          return strSQL;
     }

     Type t = obj.GetType();//獲得該類的Type

     strSQL.Append("update " + tableName + " set ");

     string subSQL = "";

     string condition = " where " + tableKey + "='" + keyValue.Replace("'", "''") + "'";


     //再用Type.GetProperties獲得PropertyInfo[]
     foreach (PropertyInfo pi in t.GetProperties())
     {

          object name = pi.Name;//用pi.GetValue獲得值

          // 替換Sql注入符
          string value1 = Convert.ToString(pi.GetValue(obj, null)).Replace("'", "''");

          //string dataType = pi.PropertyType.ToString().ToLower();

          string properName = name.ToString().ToLower();

          if (!string.IsNullOrEmpty(value1) && properName != tableKey.ToLower() && properName != BaseSet.PrimaryKey.ToLower() && properName != BaseSet.TableName.ToLower() && value1 != BaseSet.DateTimeLongNull && value1 != BaseSet.DateTimeShortNull)
          {
               // 判斷是否爲空
               if (value1 == BaseSet.NULL)
               {
                   value1 = "";
               }

               subSQL += Convert.ToString(name) + "='" + value1 + "',";

          }

     }

     // 去掉最後一個,
     subSQL = subSQL.TrimEnd(',');

     // 拼接上更新子句
     strSQL.Append(subSQL);

     // 加入更新條件
     strSQL.Append(condition);

     return strSQL;

}

public class BaseSet
{
    public static string NULL
    {
         get { return "@null"; }

    }

    public static string DateTimeShortNull
    {
         get { return "0001-1-1 0:00:00"; }

    }

    public static string DateTimeLongNull
    {
         get { return "0001-01-01 00:00:00"; }

    }

    public static string PrimaryKey
    {
         get { return "PrimaryKey"; }

    }

    public static string TableName
    {
         get { return "TableName"; }

    }
}

#region 實體樣例
[Serializable]
public class SortsInfo
{
     private int _SortID;
     private string _SortName;
     public string TableName
     {
         get { return "Sorts"; }
     }
     public string PrimaryKey
     {
         get { return "SortID"; }
     }
     public int SortID
     {
         get { return _SortID; }
         set
         {
             _SortID = value;
         }
     }
     public string SortName
     {
         get { return _SortName; }
         set
         {
             _SortName = value;
         }
     }

}

#endregion