我如何将Command.ExecuteScalar（）转换为可空类型？

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问题描述

private static int GenerationId()
{
    OleDbCommand Command = new OleDbCommand();
    Command.Connection = ConnectionDB.OLEConnection;

    Command.CommandText = "Select MAX(Client_ID) from Client";
    ConnectionDB.OLEConnection.Open();


    int? Client_ID = (int?)CommandGenerationId.ExecuteScalar(); //i get exception here


    ConnectionDB.OLEConnection.Close();
    return (int)Client_ID;
}

推荐答案

Object tempVal = CommandGenerationId.ExecuteScalar();
Int32 returnVal;

if (tempVal != null)
    returnVal = Int32.Parse(tempVal);

这些内容。对我来说，这种方法比尝试将其塞入一行更好。

Something along those lines. For me, this approach works better than trying to cram it into a single line.

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