Here is a app script code which uses a Google sheet to retrive the values. Make sure to add the Admin SDK service to the project, Also make sure to replace necessary parameters in the below code. This I had designed for a Custom Schema with one Category and Single Valued Field.
function myFunction() {
var app = SpreadsheetApp;
var ss = app.openById("Sheet ID here"); // Add your sheet ID here
var sheet = ss.getSheetByName("Sheet1"); // Add your sheet name here
var lr = sheet.getLastRow();
var optArgs = {
projection: "full",
};
var category_cs = "Privileges"; // fill in your Custom Schema Category.
var field_cs = "Privileges"; // Fill in your custom schema field.
for (var i = 2; i <= lr; i++) {
// get status from sheet if already updated
var update_status = sheet.getRange(i, 3).getValue();
// Check status if already updated
if (update_status != "Yes") {
var userEmail = sheet.getRange(i, 1).getValue(); // get email addresses are in the 1st column
var customSchemaValue = sheet.getRange(i, 2).getValue(); // get the values of custom schema from the 2nd column
// checking if user has any custom schema
var load = AdminDirectory.Users.get(userEmail, optArgs);
var schema = load.customSchemas || {};
// dynamically updating the schema with values in each iteration
schema[category_cs] = schema[category_cs] || {};
schema[category_cs][field_cs] = customSchemaValue;
// Update the user's custom schemas using Admin SDK
load.customSchemas = schema;
AdminDirectory.Users.update(load, userEmail);
// set the status as yes once updated in the sheet
sheet.getRange(i, 3).setValue("Yes");
}
}
}