topic Re: Searchin multiple fields using QueryTask in ArcGIS API for Silverlight Questions

Searchin multiple fields using QueryTask

gabrielvazquez — Wed, 11 Jan 2012 12:35:20 GMT

Using query task to search a rest service and populate various comboboxes and sorting the results using LINQ. Users can then use the comboboxes and another query task to recieve graphic results from the rest service. This works fine when I query individual fields, however I want to be able to let the user search by multiple comboboxes and I thought I could use a querytask and the query.where option to do so.

For example, something like where GISStateName = 'Maryland' AND GISIncidentType = 'BombThreat'. But in this case it might look something like

query.Text = StateNameCombobox.SelectedItem.ToString() AND IncidentNameComboBox.SelectedItem.ToString();

However, I'm not sure if this is even possible or what the correct syntax would be. I have tried a few different ways, but I cant seem to get anything to work.

I can do this with one field, e.g,
query.Text = StateNameComboBox.SelectedItem.ToString(); But not with mutiple field parameters.

Is there a way to use querytask to search multiple fields within a rest service? If so does anyone have any examples. I've looked at the concept and API examples below, but the information I am looking for.

http://help.arcgis.com/en/webapi/silverlight/help/index.html#/Query_task/01660000001t000000/
http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#AttributeQuery

Re: Searchin multiple fields using QueryTask

DarinaTchountcheva — Wed, 11 Jan 2012 13:55:39 GMT

Gabriel,

You can perform a query using multiple fields, but you will have to use the "Where" property of the "Query" object instead of "Text".

http://help.arcgis.com/en/webapi/silverlight/apiref/ESRI.ArcGIS.Client~ESRI.ArcGIS.Client.Tasks.Query_members.html

Search the API Reference for more info:

http://help.arcgis.com/en/webapi/silverlight/apiref/api_start.htm

Re: Searchin multiple fields using QueryTask

gabrielvazquez — Wed, 11 Jan 2012 14:49:22 GMT

darinatch;162367 wrote:
Gabriel,

You can perform a query using multiple fields, but you will have to use the "Where" property of the "Query" object instead of "Text".

Yes, sorry I should have said I have been trying to use query.Where also, however I am still having issues formatting the query. The code states it will accept SQL statements

Where A where clause for the query. Any legal SQL where clause operating on the fields in the layer is allowed, for example: where=POP2000 > 350000 .
However, there is any more detail and when I try code a simple query.where it does not work. I've tried it various ways, but it continues to not work. Wasnt sure if someone else has had success in using this example.

Re: Searchin multiple fields using QueryTask

gabrielvazquez — Wed, 11 Jan 2012 15:29:56 GMT

I was able to find the thread below, which helps in better understanding the Query.Where syntax.

http://forums.arcgis.com/threads/28868-Query-Syntax

Re: Searchin multiple fields using QueryTask

gabrielvazquez — Wed, 11 Jan 2012 16:06:03 GMT

K. I figured it out somewhat. But I wish ESRI would post more information on how to format the "Where" property of the "Query" object.

I was able to do the following, but still trying to figure out how to look at multiple fields.

query.Where = "StateName = '" + StateComboBox.SelectedItem + "'";

or for specific text

query.Where = "StateName = '" + "Maryland" + "'";

This should work for multiple fields, forgot you need &&.

query.Where = "StateName = '" + StateComboBox.SelectedItem+ " ' " && "IncidentType = '" + IncidentTypeComboBox +" ' ";

Just have to fool around with it some more. Actuall the use of the above && operator or &, or AND do not work when searching for strings for multiple fields.

Re: Searchin multiple fields using QueryTask

gabrielvazquez — Wed, 11 Jan 2012 16:32:25 GMT

Figured it out, was confusing linq and sql. Replaced the && with AND and removed the extra " mark I had before the && operator.

Incorred
query.Where = "StateName = '" + StateComboBox.SelectedItem+ " ' " && "IncidentType = '" + IncidentTypeComboBox +" ' ";

Correct
query.Where = "StateName = '" + StateComboBox.SelectedItem+ " ' AND "IncidentType = '" + IncidentTypeComboBox +" ' ";

Re: Searchin multiple fields using QueryTask

DaveTimmins — Wed, 11 Jan 2012 20:23:07 GMT

Hi,

I posted a related topic that may be of help here http://davetimmins.wordpress.com/2011/09/09/fluent-where-clause/

Cheers,

Re: Searchin multiple fields using QueryTask

gabrielvazquez — Thu, 12 Jan 2012 12:50:50 GMT

Hi,

I posted a related topic that may be of help here http://davetimmins.wordpress.com/2011/09/09/fluent-where-clause/

Cheers,

Great link, thank you very much.

Re: Searchin multiple fields using QueryTask

ashash — Fri, 16 Aug 2013 08:20:05 GMT

hi...
i'm having the same problem exactly like this..
can someone show me is the code works or not..
please...