如何在C＃中的內聯SQL語句的插入語句之后返回新創建的ID？

Question

[HttpPost]
public void InsertOrUpdateDirector(Director director)
{
    int idReturned = 0;

    string query = null;
    myConnection.Open();
    if (director.Operation == 'I')
    {
      query = "INSERT...";
    }
    else if (director.Operation == 'U')
    {
      query = "UPDATE ...";
    }
    var cmd = new SqlCommand(query, myConnection);
    cmd.ExecuteNonQuery();
    myConnection.Close();

    idReturned = "???";

    return idReturned;
}

我只是想在插入語句之后返回新創建的ID。 我該怎么做呢？

Answer 1

插入后，將其添加到查詢SELECT SCOPE_IDENTITY() 。 並打電話

idReturned = cmd.ExecuteScalar();

而不是cmd.ExecuteNonQuery()

然后檢查idReturned是否為null，cmd.ExecuteScalar（）將為您的更新查詢返回null，主鍵應該是Director對象的參與者，因此您可以執行以下操作：

if(idReturned == null){
    return director.DirectorId //just guessing at name of id property here for example sake
}else{
    return idReturned;
}

您應該已經將主鍵傳遞給InsertOrUpdateDirector來編寫更新查詢。

Answer 2

 Try this code,I hope this will work
myConnection.Open();
    if (director.Operation == 'I')
        {
          query = "INSERT...";
    string query1="select  createdId  from table";

        }
    var cmd = new SqlCommand(query, myConnection);
    Sqlcommand cmd1=new SqlCommand(query1,myConnection);
        cmd.ExecuteNonQuery();
    int CreatedId=cmd1.ExecuteScalar();
    return  CreatedId;
        myConnection.Close();
     myConnection.Close();