如何在C＃中的内联SQL语句的插入语句之后返回新创建的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;
}

我只是想在插入语句之后返回新创建的ID。 我该怎么做呢？

Answer 1

插入后，将其添加到查询SELECT SCOPE_IDENTITY() 。 并打电话

idReturned = cmd.ExecuteScalar();

而不是cmd.ExecuteNonQuery()

然后检查idReturned是否为null，cmd.ExecuteScalar（）将为您的更新查询返回null，主键应该是Director对象的参与者，因此您可以执行以下操作：

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

您应该已经将主键传递给InsertOrUpdateDirector来编写更新查询。

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();