C # SQL package (4)
This article is connected to C#SQL encapsulation (3)
Continue to expand on its functionality, let's get started...
One: Build T-SQL statements (add a method UPDATE_T_SQL to SQL_Structure.cs to build T-SQL for update)
/// ///Update the T-SQL composition of a piece of data (delete with id) /// /// ///original model ///modified model /// public static string UPDATE_T_SQL(T model , T model_change) where T : BaseModel { Type model_type = model.GetType(); Type model_change_type = model_change.GetType(); if (model_type.Name == model_change_type.Name) { string base_update = @"update [{0}] set {1} where {2} = @{3}"; string[] arr = model_type.Name.Split(new char[] { '. ' }); string table_name = arr[arr.Length - 1];//Get table name PropertyInfo[] p_intos = model_type.GetProperties(); PropertyInfo item = null; PropertyInfo item_change = null; string item_value = string.Empty; string item_change_value = string.Empty; StringBuilder update_set = null; for (int i = 0; i
< p_intos.Length; i++) { item = p_intos[i]; item_change = model_change_type.GetProperty(item.Name); item_value = item.GetValue(model, null).ToString(); item_change_value = item_change.GetValue(model_change, null).ToString(); if (item.Name == "id") { //比较id值是否一致 if (item_value != item_change_value) { throw new Exception( string.Format("model类 id : {0} 与model_change类id:{1} 不一致,请确保是同一条数据", item_value, item_change_value ) ); } } else { if (item_value != item_change_value) { if (update_set == null) update_set = new StringBuilder(); update_set.Append( string.Format( @" {0} = @{1}," , item.Name , item.Name ) ); } } } if (update_set != null) { return string.Format( base_update, table_name, update_set.ToString().Substring(0, update_set.ToString().Length - 1), "id", "id" ); } else { return string.Empty;//不存在更新 } } else { throw new Exception( string.Format("model类 : {0} 与model_change类 :{1} 不匹配", model_type.Name , model_change_type.Name ) ); } } 二 ： 构建SqlParameter参数 （在SqlParameter_Structure.as中添加方法UPDATE_T_SQL） /// /// 构建T-SQL参数 UPDATE /// /// /// 原model /// 更改后model /// public static SqlParameter[] UPDATE_T_SQL(T model, T model_change) where T : BaseModel { Type model_type = model.GetType(); Type model_change_type = model_change.GetType(); if (model_type.Name == model_change_type.Name) { PropertyInfo[] p_intos = model_type.GetProperties(); PropertyInfo item = null; PropertyInfo item_change = null; string item_value = string.Empty; string item_change_value = string.Empty; List sql_param = null; SqlParameter cell = null; bool is_change_model = false;//是否有字段进行了更改 for (int i = 0; i < p_intos.Length; i++) { item = p_intos[i]; item_change = model_change_type.GetProperty(item.Name); item_value = item.GetValue(model, null).ToString(); item_change_value = item_change.GetValue(model_change, null).ToString(); if (item.Name == "id") { if (item_value != item_change_value) { throw new Exception( string.Format("model类 id : {0} 与model_change类id:{1} 不一致,请确保是同一条数据", item_value, item_change_value ) ); } else { if (sql_param == null) sql_param = new List(); cell = new SqlParameter(item.Name, SqlParameter_Structure.Get_SqlDbType_SqlType(item.PropertyType)); cell.Value = item.GetValue(model, null); sql_param.Add(cell); } } else { if (item_value != item_change_value) { if (!is_change_model) is_change_model = true; if (sql_param == null) sql_param = new List(); cell = new SqlParameter(item_change.Name, SqlParameter_Structure.Get_SqlDbType_SqlType(item_change.PropertyType)); cell.Value = item_change.GetValue(model_change, null);//加入改变的值 sql_param.Add(cell); } } } if (is_change_model) { return sql_param.ToArray(); } else { return null;//没有任何字段更改 } } else { throw new Exception( string.Format("model类 : {0} 与model_change类 :{1} 不匹配", model_type.Name, model_change_type.Name ) ); } } 测试： 测试代码 //------------------------模拟一条重数据库得到的数据 begin --------------------------------------- User kayer_ori = new User(); kayer_ori.id = 3; kayer_ori.name = "kayer"; kayer_ori.sex = 1; kayer_ori.lv = 1; kayer_ori.username = "Kayer"; kayer_ori.userpwd = "123"; //------------------------模拟一条重数据库得到的数据 end ----------------------------------------- //拷贝一条kayer_ori数据 （ 可以用原型模式 ， 这里我直接使用笨办法 ） User kayer_change_copy = new User(); kayer_change_copy.id = kayer_ori.id; kayer_change_copy.name = kayer_ori.name; kayer_change_copy.sex = kayer_ori.sex; kayer_change_copy.lv = kayer_ori.lv; kayer_change_copy.username = kayer_ori.username; kayer_change_copy.userpwd = kayer_ori.userpwd; // --- 改变数据 --- kayer_change_copy.name = "Aonaufly"; kayer_change_copy.lv = 4; string sql_update = SQL_Structure.UPDATE_T_SQL(kayer_ori, kayer_change_copy); SqlParameter[] update_p = SqlParameter_Structure.UPDATE_T_SQL(kayer_ori, kayer_change_copy); int i = SqlHelper.ExecteNonQuery(CommandType.Text, sql_update, update_p); if (i >0)
{
Console.WriteLine("Execution succeeded");
}
else
{
Console.WriteLine("Failed to perform operation");
}
Results:
In the database:
To be continued.....................................................................................
