获取mssqlserver与access数据库插入的当前行的id

//mssqlserver
 public static int GetInsertId(string sql)
    {
        try
        {
            SqlCommand cmd = new SqlCommand();
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                PrepareCommand(cmd, conn, sql, null);
                cmd.ExecuteNonQuery();
                PrepareCommand(cmd, conn, "Select @@Identity", null);
                int val = Convert.ToInt32(cmd.ExecuteScalar());
                return val;
            }
        }
        catch (Exception err)
        {
            throw err;
        }

    }

private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, string CmdText, SqlTransaction trans)
    {
        try
        {
            if (conn.State != ConnectionState.Open)
            {
                conn.Open();
            }
            cmd.Connection = conn;
            cmd.CommandText = CmdText;
            if (trans != null)
            {
                cmd.Transaction = trans;
            }
            cmd.CommandType = CommandType.Text;
        }
        catch (Exception err)
        {
            throw err;
        }
    }

//access
public static int GetInsertId(string sql)
    {
        try
        {
            OleDbCommand cmd = new OleDbCommand();
            using (OleDbConnection conn = new OleDbConnection(ConnectionString))
            {
                PrepareCommand(cmd, conn, sql, null);
                cmd.ExecuteNonQuery();
                PrepareCommand(cmd, conn, "Select @@Identity", null);
                int val =Convert.ToInt32( cmd.ExecuteScalar());
                return val;
            }
        }
        catch (Exception err)
        {
            throw err;
        }

    }

public static void PrepareCommand(OleDbCommand cmd, OleDbConnection conn, string CmdText, OleDbTransaction trans)
    {
        try
        {
            if (conn.State != ConnectionState.Open)
            {
                conn.Open();
            }
            cmd.Connection = conn;
            cmd.CommandText = CmdText;
            if (trans != null)
            {
                cmd.Transaction = trans;
            }
            cmd.CommandType = CommandType.Text;
        }
        catch (Exception err)
        {
            throw err;
        }
    }

//还有一种可以用通过插入后查询当前表的最大id的方法获取，但是如果数据并发量大可能回出现问题