c# - 如何获取 LAST_INSERT_ID()；

Question

我环顾四周，仍然对如何获取最后插入的 ID 感到困惑。我在正在执行的 mysql 语句末尾添加了语句 SELECT LAST_INSERT_ID();。我将值存储在 prID = Convert.ToInt32(cmd.ExecuteScalar()); 此命令在我的数据库中创建两个实例。我很确定我需要将这两个语句分开，但不确定如何在仍然获得最后一个 ID 的同时。

          try
            {
                Console.WriteLine("Connecting to MySQL...");
                conn.Open();
                string sql = "INSERT INTO pull_requests (repoID, branchID, fileID, prStatus, prComments) VALUES (@rID, @bID, @fID, @prS, @prC); SELECT LAST_INSERT_ID();";
                MySql.Data.MySqlClient.MySqlCommand cmd = new MySql.Data.MySqlClient.MySqlCommand(sql, conn);
                cmd.Parameters.AddWithValue("@rID", RI);
                cmd.Parameters.AddWithValue("@bID", BI);
                cmd.Parameters.AddWithValue("@fID", FI);
                cmd.Parameters.AddWithValue("@prS", 0);
                cmd.Parameters.AddWithValue("@prC", comment);
                prID = Convert.ToInt32(cmd.ExecuteScalar());

                cmd.ExecuteNonQuery();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
            conn.Close();

Answer 1

您只需调用cmd.ExecuteNonQuery() 即可执行插入语句。返回时，cmd 对象将填充其 .LastInsertedId 属性。

像这样:

try
{
    Console.WriteLine("Connecting to MySQL...");
    conn.Open();
    string sql = "INSERT INTO pull_requests (repoID, branchID, fileID, prStatus, prComments) VALUES (@rID, @bID, @fID, @prS, @prC);";
    MySql.Data.MySqlClient.MySqlCommand cmd = new MySql.Data.MySqlClient.MySqlCommand(sql, conn);
    cmd.Parameters.AddWithValue("@rID", RI);
    cmd.Parameters.AddWithValue("@bID", BI);
    cmd.Parameters.AddWithValue("@fID", FI);
    cmd.Parameters.AddWithValue("@prS", 0);
    cmd.Parameters.AddWithValue("@prC", comment);
    cmd.ExecuteNonQuery();

    long lastId = cmd.LastInsertedId;
}
catch (Exception ex)
{
    Console.WriteLine(ex.ToString());
}
conn.Close();