//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;        }    }//accesspublic 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