diff --git a/server/src/models/segment_model.ts b/server/src/models/segment_model.ts
index bc46b9c..507622a 100644
--- a/server/src/models/segment_model.ts
+++ b/server/src/models/segment_model.ts
@@ -5,7 +5,7 @@ import { Collection, makeDBQ } from '../services/data_service';
 let db = makeDBQ(Collection.SEGMENTS);
 
 
-type SegmentId = string;
+export type SegmentId = string;
 
 export class Segment {
   constructor(
@@ -64,7 +64,7 @@ export type FindManyQuery = {
 }
 
 export async function findMany(id: AnalyticUnitId, query: FindManyQuery): Promise<Segment[]> {
-  var dbQuery: any = { auId: id };
+  var dbQuery: any = { analyticUnitId: id };
   if(query.timeFromGTE !== undefined) {
     dbQuery.from = { $gte: query.timeFromGTE };
   }
@@ -72,6 +72,9 @@ export async function findMany(id: AnalyticUnitId, query: FindManyQuery): Promis
     dbQuery.to = { $lte: query.timeToLTE };
   }
   let segs = await db.findMany(dbQuery);
+  if(segs === null) {
+    return [];
+  }
   return segs.map(Segment.fromObject);
 }
 
diff --git a/server/src/routes/segments_router.ts b/server/src/routes/segments_router.ts
index a03d8c3..07bc1fc 100644
--- a/server/src/routes/segments_router.ts
+++ b/server/src/routes/segments_router.ts
@@ -7,30 +7,47 @@ import { runLearning } from '../controllers/analytics_controller';
 
 
 async function getSegments(ctx: Router.IRouterContext) {
-  // let id: AnalyticUnitId = ctx.request.query.id;
+  let id: AnalyticUnitId = ctx.request.query.id;
+  if(id === undefined || id === '') {
+    throw new Error('analyticUnitId (id) is missing');
+  }
+  let query: SegmentModel.FindManyQuery = {};
+
+  if(!isNaN(+ctx.request.query.lastSegmentId)) {
+    query.intexGT = +ctx.request.query.lastSegmentId;
+  }
+  if(!isNaN(+ctx.request.query.from)) {
+    query.timeFromGTE = +ctx.request.query.from;
+  }
+  if(!isNaN(+ctx.request.query.to)) {
+    query.timeToLTE = +ctx.request.query.to;
+  }
 
-  // let segments = await findMany(id, {
-  //   intexGT: ctx.request.query.lastSegmentId, 
-  //   timeFromGTE:  ctx.request.query.from, 
-  //   timeToLTE: ctx.request.query.to
-  // });
+  let segments = await SegmentModel.findMany(id, query);
 
-  ctx.response.body = { segments: [] };
+  ctx.response.body = { segments };
 
 }
 
 async function updateSegments(ctx: Router.IRouterContext) {
   try {
-    
-    let { addedSegments, id } = ctx.request.body as { addedSegments: any[], id: AnalyticUnitId };
+
+    let {
+      addedSegments, id, removedSegments: removedIds
+    } = ctx.request.body as {
+      addedSegments: any[], id: AnalyticUnitId, removedSegments: SegmentModel.SegmentId[]
+    };
 
     let segmentsToInsert: SegmentModel.Segment[] = addedSegments.map(
       s => SegmentModel.Segment.fromObject({ analyticUnitId: id, labeled: true, ...s })
     );
-    
-    let addedIds = await SegmentModel.insertSegments(segmentsToInsert);
-    // removeSegments(id, segmentsUpdate.removedSegments);
-    ctx.response.body = { addedIds };
+
+    let [addedIds, removed] = await Promise.all([
+      SegmentModel.insertSegments(segmentsToInsert),
+      SegmentModel.removeSegments(removedIds)
+    ]);
+
+    ctx.response.body = { addedIds, removed };
     runLearning(id);
   } catch(e) {
     ctx.response.status = 500;
diff --git a/server/src/services/data_service.ts b/server/src/services/data_service.ts
index e892c99..ec9908c 100644
--- a/server/src/services/data_service.ts
+++ b/server/src/services/data_service.ts
@@ -48,6 +48,13 @@ function wrapIdsToQuery(query: string[] | object): any {
   return query;
 }
 
+function isEmptyArray(obj: any): boolean {
+  if(!Array.isArray(obj)) {
+    return false;
+  }
+  return obj.length == 0;
+}
+
 const db = new Map<Collection, nedb>();
 
 let dbInsertOne = (collection: Collection, doc: object) => {
@@ -104,9 +111,12 @@ let dbFindOne = (collection: Collection, query: string | object) => {
 }
 
 let dbFindMany = (collection: Collection, query: string[] | object) => {
+  if(isEmptyArray(query)) {
+    return Promise.resolve([]);
+  }
   query = wrapIdsToQuery(query);
   return new Promise<any[]>((resolve, reject) => {
-    db.get(collection).findOne(query, (err, docs: any[]) => {
+    db.get(collection).find(query, (err, docs: any[]) => {
       if(err) {
         reject(err);
       } else {
@@ -116,15 +126,15 @@ let dbFindMany = (collection: Collection, query: string[] | object) => {
   });
 }
 
-let dbRemoveOne = (collection: Collection, id: string) => {
-  let query = { _id: id };
+let dbRemoveOne = (collection: Collection, query: string | object) => {
+  query = wrapIdToQuery(query);
   return new Promise<boolean>((resolve, reject) => {
-    db.get(collection).remove(query, (err, numRemoved) => {
+    db.get(collection).remove(query, { /* options */ }, (err, numRemoved) => {
       if(err) {
         reject(err);
       } else {
         if(numRemoved > 1) {
-          throw new Error(`Removed ${numRemoved} elements with id: ${id}. Only one is Ok.`);
+          throw new Error(`Removed ${numRemoved} elements with query: ${JSON.stringify(query)}. Only one is Ok.`);
         } else {
           resolve(numRemoved == 1);
         }
@@ -134,9 +144,12 @@ let dbRemoveOne = (collection: Collection, id: string) => {
 }
 
 let dbRemoveMany = (collection: Collection, query: string[] | object) => {
+  if(isEmptyArray(query)) {
+    return Promise.resolve([]);
+  }
   query = wrapIdsToQuery(query);
   return new Promise<number>((resolve, reject) => {
-    db.get(collection).remove(query, (err, numRemoved) => {
+    db.get(collection).remove(query, { multi: true }, (err, numRemoved) => {
       if(err) {
         reject(err);
       } else {
@@ -146,7 +159,6 @@ let dbRemoveMany = (collection: Collection, query: string[] | object) => {
   });
 }
 
-
 function maybeCreateDir(path: string): void {
   if(fs.existsSync(path)) {
     return;