一旦我将其写入数据库，如何更新类？ [英] How Do I Update A Class Once I've Written It To A Database?

问题描述

大家好



我正在写一个遥测程序来跟踪比赛的所有信息。

每场比赛是一个在Session表中记录它自己。



数据库表包含以下字段：



[ SessionID]（主键）

[日期]

[位置]（外键）

[驱动程序]（外键）

[评论]

[EngineSetup]

[GearingSetup]

[TyreSetup]

[ BrakeSetup]

[SkyConditions]

[温度]

[WindSpeed]

[下雨]



我的C＃应用​​程序中的Session类具有相同的字段，减去数据库生成的SessionID。



在我的Session类中有一个Create（）方法，它调用

DATA ACESS LAYER中的方法，该方法执行存储过程以在会话表中创建记录。



我的问题是这个：



一旦我解雇了Session.Create（）方法，无论如何都要检索数据库生成的sessionID并将其分配给同一个会话宾语？



我的Session类中有一个构造函数，可以使用SessionID作为Session对象进行编辑。

Hi All

I'm writing a telemetry program which keeps track of all information from a race.
each race is a record on it's own within the Session table.

the database table contains the following fields:

[SessionID](Primary Key)
[Date]
[Location](Foreign Key)
[Driver](Foreign Key)
[Comments]
[EngineSetup]
[GearingSetup]
[TyreSetup]
[BrakeSetup]
[SkyConditions]
[Temperature]
[WindSpeed]
[Rain]

The Session class in my C# application has the same fields, minus the SessionID which is generated by the Database.

Within my Session class there is a Create()method, which calls a method in the
DATA ACESS LAYER, which in executes the stored procedure to create the record in the Session Table.

My question is this:

once I've fired off the Session.Create() method, is there anyway to retrieve the sessionID generated by the database and assign it to the same session object?

I have a constructor in my Session class that can take a Session object with a SessionID for editing purposes.

推荐答案

亲爱的，

Dear,

/* 1. Add below into your parameter list in store procedure */

@SessionID <datatype> OUTPUT

/* 2. Write down your insert statement */

/* 3. Set last inserted identity to declared variable */

SET @SessionID = @@IDENTITY

</datatype>

您的C＃代码如下：

Your C# code as below :

string returnVal;

SqlParameter myValue = new SqlParameter();
myValue.ParameterName = "@SessionID";
myValue.Direction = ParameterDirection.Output;
myValue.DbType = <your dbtype  as per table structure>;
myCmd.Parameters.Add(myValue);
myCmd.ExecuteNonQuery();
returnVal = Convert.ToString(myValue.Value);

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