Simple SQL Query, .net

SP2501

This is probably going to be a simple answer, but im having some trouble formatting an SQL query in C#.

I need to query a featuretable and pick out a feature that has a matching "fips". 

the feature name is a string, example shows a number but they can be strings.

When I use the following code, I keep getting a return (featureresult2) of ALL the features in the table. I have tried a few different ways of phrasing the query, but it seems I am missing something.

name = S.UniqueID; 

//Lets look up the geometry
string s = "fips";
string columnName = s;
string searchString = name;
// string sqlQuery = $"{columnName} = {searchString}";//Returning all
string sqlQuery = "fips = '270530265081'"; //Testing simple, still returning all

QueryParameters queryParams = new QueryParameters //Selects the fips
{
WhereClause = sqlQuery
};
FeatureQueryResult featureResult2;
featureResult2 = (BlockGroupGeoPackage.GeoPackageFeatureTables[0].QueryFeaturesAsync(queryParams).GetAwaiter().GetResult());

 

 

 

JenniferNery

I don't see anything wrong with how you formed the query. String equality looks correct provided the field exists with the correct name and type. If you want query to return just one, you can set MaxFeatures = 1; but if you say this value is unique then you should expect a single feature returned without MaxFeatures.

var attributeValue = "270530265081";

var table = BlockGroupGeoPackage.GeoPackageFeatureTables[0];
var tableField = table.GetField("fips");


var query = new QueryParameters()
{
  WhereClause = $"{tableField.Name} = '{attributeValue}'",
  MaxFeatures = 1
};

I would await the result of query though and may be inspect the features that come back. Output window should have the attribute value for each feature.

var features = await table.QueryFeaturesAsync(query);

foreach(var feature in features)
{
  // Consider printing other attributes to identify the feature (i.e. OBJECTID)
  System.Diagnostics.Debug.WriteLine($"{tableField.Name}: feature.Attribute[tableField.Name]")
}