Cascading DDL using non-id variable [Answered]RSS

• • Reply
  ReidMelSam

  Member

  14 Points

  308 Posts

  Cascading DDL using non-id variable

  Jan 23, 2019 04:51 PM|ReidMelSam|LINK

  Hi,

  I have a select list on my MVC page to select a state:

  <div class="form-group">
          @Html.LabelFor(m=> m.State, new { @class = "control-label" })
          @Html.DropDownListFor((m => m.State, ViewBag.Statelist as SelectList, "- - select State - -"))
      </div>

  ...where "State" is NOT the "StateId" but rather a variable "State" that is text i.e; "CA" or "LA" etc.

  My issue is that I want to use the selected "State", say "CA" to populate a list of stores in the selected state. The "Stores" table has addresses with "State" to compare to my selected "State", but not "StateId":

  Store	Address	CityName	State	ZipCode
  Store 1001	101 Main St	Los Angeles	CA	90201
  Store 1005	203 First St	Alameda	CA	94533
  Store 3003	999 Dock Street	San Francisco	CA	94502

  ...and so on. So I want the selected "State", "CA" to compare to the "State" column in the stores table, not to a "StateId" which is not present in the "stores" table.

  I may also need to do a double cascade to compare a selected city name like "San Diego" to isolate stores just from that city. This would give me a third ddl, "Stores" from which I can select the desired "Store."

  My question:  Is there a way to populate ddl starting from a "State" table but using the text "CA" as the selected value, and then even choose a "CityName" from the stores table as a value to get the final stores list?

  If anyone can point me to some examples of ddl based upon text values instead of "id" values, plz reply. For all I know, this may be common. I have never done cascading, so I'm in the early learning phase. Problem is, I have a "State" table, but not a "City" table with "StateId" and "CityId." Also, no "StateId" nor "CityId" in the "Stores" table I want to read from.

  Thanks much!

  "Look at it go, Homer; this one's gonna go for miles!"
• • Reply
  bruce (sqlwo...

  All-Star

  50844 Points

  12086 Posts

  Re: Cascading DDL using non-id variable

  Jan 23, 2019 11:35 PM|bruce (sqlwork.com)|LINK

  the DropDownList generate a <select> with <options>. the options has an optional value and a text prop:

  <select>
    <option>text1</option>
    <option>text2</option>
  </select>
  

  in this case the as the value is not specified, it defaults to the text. you can add a value attribute

  <select>
    <option value="text1">text1</option>
    <option value="text2">text2</option>
  </select>

  if you don't want a value, its just

    var list = new SelectList(new string[] {"CA","OR","WA"});

  bruce (sqlwork.com)
• • Reply
  ReidMelSam

  Member

  14 Points

  308 Posts

  Re: Cascading DDL using non-id variable

  Jan 24, 2019 12:27 AM|ReidMelSam|LINK

  Bruce,

  Thanks. I'm such a code dummy, I can't easily translate your static list example to my MVC model/table problem. But it sounds like you're just telling me that I should use as the "Value" the column of "State" symbols ("CA", "OR" etc.) rather than the int "StateId" and I'll be fine?

  Thanks again for any ideas.

  "Look at it go, Homer; this one's gonna go for miles!"
• • Reply
  Yuki Tao

  Contributor

  2180 Points

  934 Posts

  Re: Cascading DDL using non-id variable

  Jan 30, 2019 08:22 AM|Yuki Tao|LINK

  Hi ReidMelSam,

  ReidMelSam

  My issue is that I want to use the selected "State", say "CA" to populate a list of stores in the selected state. The "Stores" table has addresses with "State" to compare to my selected "State", but not "StateId":

  Actually,this is related to ViewBag.Statelist as SelectList.

  For example:

  In controller:

  ViewBag.StateList = new SelectList(datasource, "xx1", "xx2"); 

  you just exchange xx1 and xx2 positions,like:

  ViewBag.StateList = new SelectList(datasource, "xx2", "xx1"); 

  And you could refer to this link about Cascading DDL:

  https://forums.asp.net/post/6236282.aspx

  Best Regards.

  Yuki Tao

  Please remember to "Mark as Answer" if suggestion helps.
• • Reply
  ReidMelSam

  Member

  14 Points

  308 Posts

  Re: Cascading DDL using non-id variable

  Feb 05, 2019 10:38 PM|ReidMelSam|LINK

  Thank you for the info. I was hung up on the idea of not using an int column like an "Id" as a "WHERE" parameter. But using the "State" symbol column, a string (like "AL", "CA" or "NY") as the parameter was just as good.

  Thanks again!

  "Look at it go, Homer; this one's gonna go for miles!"