选择，计数和使用codeigniter和mysql的位置

I have two table as follow:

我有两张表如下：

- tblSaler

    SalerID  |  SalerName | 
    ----------------------|
    1        |  sothorn   |
    ----------------------|
    2        |  Daly      |  
    ----------------------|
    3        |  Lyhong    |
    ----------------------|
    4        | Chantra    |
    ----------------------|

- tblProduct

ProductID  | Product  | SalerID |
--------------------------------|
1          | Pen      | 3       |
--------------------------------|
2          | Book     | 2       |
--------------------------------|
3          | Phone    | 3       |
--------------------------------|
4          | Computer | 1       |
--------------------------------|
5          | Bag      | 3       |
--------------------------------|
6          | Watch    | 2       |
--------------------------------|
7          | Glasses  | 4       |
--------------------------------|
- tbl