How to use group by in query in google app script - google-apps-script

Question

I am making a query in google app script.
I am trying to do a grouping query, but it doesn't come out
var spreadsheetId_2 = '1Z6_d0CaY38VvfPaWi0-5XRRpitKFmy3gMJsHNiMIpiK8[';
var targetSheet_2 = 'Actividades';
var query_2 = 'select C where K = "WHITE" GROUP BY C ';
var ss_2 = SpreadsheetApp.openById(spreadsheetId_2);
var sheetId_2 = ss_2.getSheetByName(targetSheet_2).getSheetId();
var url_2 = "https://docs.google.com/spreadsheets/d/" + spreadsheetId_2 + "/gviz/tq?gid=" + sheetId_2 + "&tqx=out:csv&tq=" + encodeURIComponent(query_2);
var res_2 = UrlFetchApp.fetch(url_2, {headers: {Authorization: "Bearer " + ScriptApp.getOAuthToken()}});
var row_2 = Utilities.parseCsv(res_2.getContentText());
var maximo_2=row_2.length;
for (var i = 1; i < maximo_2; i++) {
var pers =row_2[i][0].toString();
}
What should change?

Answer 1

You want to retrieve the values using GROUP BY of the query.
You want to know the reason that the values are not returned.
Modification points:
I think that in your query, an error occurs. By this, no values are returned. So for example, how about including count(C) as follows.
select C,count(C) where K = "WHITE" GROUP BY C.
Modified script:
When your script is modified, please modify as follows.
From:
var query_2 = 'select C where K = "WHITE" GROUP BY C ';
var ss_2 = SpreadsheetApp.openById(spreadsheetId_2);
var sheetId_2 = ss_2.getSheetByName(targetSheet_2).getSheetId();
var url_2 = "https://docs.google.com/spreadsheets/d/" + spreadsheetId_2 + "/gviz/tq?gid=" + sheetId_2 + "&tqx=out:csv&tq=" + encodeURIComponent(query_2);
var res_2 = UrlFetchApp.fetch(url_2, {headers: {Authorization: "Bearer " + ScriptApp.getOAuthToken()}});
var row_2 = Utilities.parseCsv(res_2.getContentText());
To:
var query_2 = 'select C,count(C) where K = "WHITE" GROUP BY C'; // Modified
var ss_2 = SpreadsheetApp.openById(spreadsheetId_2);
var sheetId_2 = ss_2.getSheetByName(targetSheet_2).getSheetId();
var url_2 = "https://docs.google.com/spreadsheets/d/" + spreadsheetId_2 + "/gviz/tq?gid=" + sheetId_2 + "&tqx=out:csv&tq=" + encodeURIComponent(query_2);
var res_2 = UrlFetchApp.fetch(url_2, {headers: {Authorization: "Bearer " + ScriptApp.getOAuthToken()}});
var row_2 = Utilities.parseCsv(res_2.getContentText());
row_2.shift(); // Added
Reference:
Group By