diff --git a/media-store/db/schema.cds b/media-store/db/schema.cds
index 6a88006a..18466e95 100644
--- a/media-store/db/schema.cds
+++ b/media-store/db/schema.cds
@@ -34,18 +34,24 @@ entity Albums {
     key ID     : Integer;
         title  : String(120);
         artist : Association to Artists;
+        tracks : Association to many Tracks
+                     on tracks.album = $self;
 }
 
 entity Employees : Persone {
-    reportsTo : Association to Employees;
-    title     : String(20);
-    birthDate : DateTime;
-    hireDate  : DateTime;
+    reportsTo    : Association to Employees;
+    title        : String(20);
+    birthDate    : DateTime;
+    hireDate     : DateTime;
+    subordinates : Association to many Employees
+                       on subordinates.reportsTo = $self;
 }
 
 entity Customers : Persone {
     company    : String(80);
     supportRep : Association to Employees;
+    invoices   : Association to many Invoices
+                     on invoices.customer = $self;
 }
 
 entity Invoices {
diff --git a/media-store/package.json b/media-store/package.json
index f876c74b..35ad1b7e 100644
--- a/media-store/package.json
+++ b/media-store/package.json
@@ -14,8 +14,9 @@
   },
   "scripts": {
     "start": "npx cds run",
-    "deploy:mychinookdb": "cds deploy --to sqlite:mychinook.db",
-    "import:data": "node ./util/importData.js sqlite:chinook.db sqlite:mychinook.db ./db/schema.cds"
+    "deploy": "cds deploy --to sqlite:mychinook.db",
+    "import": "node ./util/importData.js sqlite:chinook.db sqlite:mychinook.db ./db/schema.cds",
+    "test": "mocha test/media-service.test.js --verbose --timeout 10000"
   },
   "cds": {
     "requires": {
diff --git a/media-store/test/data/media-service.mock.js b/media-store/test/data/media-service.mock.js
new file mode 100644
index 00000000..11957e5a
--- /dev/null
+++ b/media-store/test/data/media-service.mock.js
@@ -0,0 +1,369 @@
+const FIRST_EMPLOYEE = {
+  "@odata.context": "$metadata#Employees/$entity",
+  ID: 1,
+  lastName: "Adams",
+  firstName: "Andrew",
+  city: "Edmonton",
+  state: "AB",
+  address: "11120 Jasper Ave NW",
+  country: "Canada",
+  postalCode: "T5K 2N1",
+  phone: "+1 (780) 428-9482",
+  fax: "+1 (780) 428-3457",
+  email: "andrew@chinookcorp.com",
+  title: "General Manager",
+  birthDate: "1962-02-17T21:00:00Z",
+  hireDate: "2002-08-13T21:00:00Z",
+  reportsTo_ID: null,
+};
+
+const SECOND_EMPLOYEE_WITH_EXPANDED_FIELDS = {
+  "@odata.context": "$metadata#Employees(subordinates(),reportsTo())/$entity",
+  ID: 2,
+  lastName: "Edwards",
+  firstName: "Nancy",
+  city: "Calgary",
+  state: "AB",
+  address: "825 8 Ave SW",
+  country: "Canada",
+  postalCode: "T2P 2T3",
+  phone: "+1 (403) 262-3443",
+  fax: "+1 (403) 262-3322",
+  email: "nancy@chinookcorp.com",
+  title: "Sales Manager",
+  birthDate: "1958-12-07T21:00:00Z",
+  hireDate: "2002-04-30T21:00:00Z",
+  reportsTo_ID: 1,
+  reportsTo: {
+    ID: 1,
+    lastName: "Adams",
+    firstName: "Andrew",
+    city: "Edmonton",
+    state: "AB",
+    address: "11120 Jasper Ave NW",
+    country: "Canada",
+    postalCode: "T5K 2N1",
+    phone: "+1 (780) 428-9482",
+    fax: "+1 (780) 428-3457",
+    email: "andrew@chinookcorp.com",
+    title: "General Manager",
+    birthDate: "1962-02-17T21:00:00Z",
+    hireDate: "2002-08-13T21:00:00Z",
+    reportsTo_ID: null,
+  },
+  subordinates: [
+    {
+      ID: 3,
+      lastName: "Peacock",
+      firstName: "Jane",
+      city: "Calgary",
+      state: "AB",
+      address: "1111 6 Ave SW",
+      country: "Canada",
+      postalCode: "T2P 5M5",
+      phone: "+1 (403) 262-3443",
+      fax: "+1 (403) 262-6712",
+      email: "jane@chinookcorp.com",
+      title: "Sales Support Agent",
+      birthDate: "1973-08-28T21:00:00Z",
+      hireDate: "2002-03-31T21:00:00Z",
+      reportsTo_ID: 2,
+    },
+    {
+      ID: 4,
+      lastName: "Park",
+      firstName: "Margaret",
+      city: "Calgary",
+      state: "AB",
+      address: "683 10 Street SW",
+      country: "Canada",
+      postalCode: "T2P 5G3",
+      phone: "+1 (403) 263-4423",
+      fax: "+1 (403) 263-4289",
+      email: "margaret@chinookcorp.com",
+      title: "Sales Support Agent",
+      birthDate: "1947-09-18T21:00:00Z",
+      hireDate: "2003-05-02T21:00:00Z",
+      reportsTo_ID: 2,
+    },
+    {
+      ID: 5,
+      lastName: "Johnson",
+      firstName: "Steve",
+      city: "Calgary",
+      state: "AB",
+      address: "7727B 41 Ave",
+      country: "Canada",
+      postalCode: "T3B 1Y7",
+      phone: "1 (780) 836-9987",
+      fax: "1 (780) 836-9543",
+      email: "steve@chinookcorp.com",
+      title: "Sales Support Agent",
+      birthDate: "1965-03-02T21:00:00Z",
+      hireDate: "2003-10-16T21:00:00Z",
+      reportsTo_ID: 2,
+    },
+  ],
+};
+
+const ALL_ALBUMS_WITH_TRACKS_BY_ARTIST = {
+  "@odata.context": "$metadata#Albums(tracks())",
+  value: [
+    {
+      ID: 1,
+      title: "For Those About To Rock We Salute You",
+      artist_ID: 1,
+      tracks: [
+        {
+          ID: 1,
+          name: "For Those About To Rock (We Salute You)",
+          composer: "Angus Young, Malcolm Young, Brian Johnson",
+          milliseconds: 343719,
+          bytes: 11170334,
+          unitPrice: 0.99,
+          album_ID: 1,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 6,
+          name: "Put The Finger On You",
+          composer: "Angus Young, Malcolm Young, Brian Johnson",
+          milliseconds: 205662,
+          bytes: 6713451,
+          unitPrice: 0.99,
+          album_ID: 1,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 7,
+          name: "Let's Get It Up",
+          composer: "Angus Young, Malcolm Young, Brian Johnson",
+          milliseconds: 233926,
+          bytes: 7636561,
+          unitPrice: 0.99,
+          album_ID: 1,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 8,
+          name: "Inject The Venom",
+          composer: "Angus Young, Malcolm Young, Brian Johnson",
+          milliseconds: 210834,
+          bytes: 6852860,
+          unitPrice: 0.99,
+          album_ID: 1,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 9,
+          name: "Snowballed",
+          composer: "Angus Young, Malcolm Young, Brian Johnson",
+          milliseconds: 203102,
+          bytes: 6599424,
+          unitPrice: 0.99,
+          album_ID: 1,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 10,
+          name: "Evil Walks",
+          composer: "Angus Young, Malcolm Young, Brian Johnson",
+          milliseconds: 263497,
+          bytes: 8611245,
+          unitPrice: 0.99,
+          album_ID: 1,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 11,
+          name: "C.O.D.",
+          composer: "Angus Young, Malcolm Young, Brian Johnson",
+          milliseconds: 199836,
+          bytes: 6566314,
+          unitPrice: 0.99,
+          album_ID: 1,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 12,
+          name: "Breaking The Rules",
+          composer: "Angus Young, Malcolm Young, Brian Johnson",
+          milliseconds: 263288,
+          bytes: 8596840,
+          unitPrice: 0.99,
+          album_ID: 1,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 13,
+          name: "Night Of The Long Knives",
+          composer: "Angus Young, Malcolm Young, Brian Johnson",
+          milliseconds: 205688,
+          bytes: 6706347,
+          unitPrice: 0.99,
+          album_ID: 1,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 14,
+          name: "Spellbound",
+          composer: "Angus Young, Malcolm Young, Brian Johnson",
+          milliseconds: 270863,
+          bytes: 8817038,
+          unitPrice: 0.99,
+          album_ID: 1,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+      ],
+    },
+    {
+      ID: 4,
+      title: "Let There Be Rock",
+      artist_ID: 1,
+      tracks: [
+        {
+          ID: 15,
+          name: "Go Down",
+          composer: "AC/DC",
+          milliseconds: 331180,
+          bytes: 10847611,
+          unitPrice: 0.99,
+          album_ID: 4,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 16,
+          name: "Dog Eat Dog",
+          composer: "AC/DC",
+          milliseconds: 215196,
+          bytes: 7032162,
+          unitPrice: 0.99,
+          album_ID: 4,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 17,
+          name: "Let There Be Rock",
+          composer: "AC/DC",
+          milliseconds: 366654,
+          bytes: 12021261,
+          unitPrice: 0.99,
+          album_ID: 4,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 18,
+          name: "Bad Boy Boogie",
+          composer: "AC/DC",
+          milliseconds: 267728,
+          bytes: 8776140,
+          unitPrice: 0.99,
+          album_ID: 4,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 19,
+          name: "Problem Child",
+          composer: "AC/DC",
+          milliseconds: 325041,
+          bytes: 10617116,
+          unitPrice: 0.99,
+          album_ID: 4,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 20,
+          name: "Overdose",
+          composer: "AC/DC",
+          milliseconds: 369319,
+          bytes: 12066294,
+          unitPrice: 0.99,
+          album_ID: 4,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 21,
+          name: "Hell Ain't A Bad Place To Be",
+          composer: "AC/DC",
+          milliseconds: 254380,
+          bytes: 8331286,
+          unitPrice: 0.99,
+          album_ID: 4,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+        {
+          ID: 22,
+          name: "Whole Lotta Rosie",
+          composer: "AC/DC",
+          milliseconds: 323761,
+          bytes: 10547154,
+          unitPrice: 0.99,
+          album_ID: 4,
+          mediaType_ID: 1,
+          genre_ID: 1,
+        },
+      ],
+    },
+  ],
+};
+
+const CUSTOMER_WITH_THEIR_SUPPORT_REP = {
+  "@odata.context": "$metadata#Customers(supportRep())/$entity",
+  ID: 1,
+  lastName: "Gonçalves",
+  firstName: "Luís",
+  city: "São José dos Campos",
+  state: "SP",
+  address: "Av. Brigadeiro Faria Lima, 2170",
+  country: "Brazil",
+  postalCode: "12227-000",
+  phone: "+55 (12) 3923-5555",
+  fax: "+55 (12) 3923-5566",
+  email: "luisg@embraer.com.br",
+  company: "Embraer - Empresa Brasileira de Aeronáutica S.A.",
+  supportRep_ID: 3,
+  supportRep: {
+    ID: 3,
+    lastName: "Peacock",
+    firstName: "Jane",
+    city: "Calgary",
+    state: "AB",
+    address: "1111 6 Ave SW",
+    country: "Canada",
+    postalCode: "T2P 5M5",
+    phone: "+1 (403) 262-3443",
+    fax: "+1 (403) 262-6712",
+    email: "jane@chinookcorp.com",
+    title: "Sales Support Agent",
+    birthDate: "1973-08-28T21:00:00Z",
+    hireDate: "2002-03-31T21:00:00Z",
+    reportsTo_ID: 2,
+  },
+};
+
+const EIGHTH_ALBUM_TRACKS_COUNT = 3290;
+
+module.exports = {
+  FIRST_EMPLOYEE,
+  SECOND_EMPLOYEE_WITH_EXPANDED_FIELDS,
+  ALL_ALBUMS_WITH_TRACKS_BY_ARTIST,
+  CUSTOMER_WITH_THEIR_SUPPORT_REP,
+  EIGHTH_ALBUM_TRACKS_COUNT,
+};
diff --git a/media-store/test/media-service.test.js b/media-store/test/media-service.test.js
new file mode 100644
index 00000000..e9a0432d
--- /dev/null
+++ b/media-store/test/media-service.test.js
@@ -0,0 +1,67 @@
+const cds = require("../../test/cds");
+const { GET, expect } = cds.test("media-store").in(__dirname, "../../");
+
+const {
+  FIRST_EMPLOYEE,
+  SECOND_EMPLOYEE_WITH_EXPANDED_FIELDS,
+  ALL_ALBUMS_WITH_TRACKS_BY_ARTIST,
+  CUSTOMER_WITH_THEIR_SUPPORT_REP,
+  EIGHTH_ALBUM_TRACKS_COUNT,
+} = require("./data/media-service.mock");
+
+describe("Media service", () => {
+  it("should bootstrap the services successfully", () => {
+    const { MediaService, db } = cds.services;
+    const { Employees } = MediaService.entities;
+
+    expect(MediaService).not.to.be.undefined;
+    expect(db).not.to.be.undefined;
+    expect(Employees).not.to.be.undefined;
+  });
+
+  describe("Employees", () => {
+    it("should return employee (ID=1)", async () => {
+      const { data } = await GET("/media/Employees(1)");
+      expect(data).to.eql(FIRST_EMPLOYEE);
+    });
+
+    it("should return employee (ID=2) with subordinates and whom he reports to", async () => {
+      const { data } = await GET(
+        `/media/Employees(2)?$expand=subordinates,reportsTo`
+      );
+      expect(data).to.eql(SECOND_EMPLOYEE_WITH_EXPANDED_FIELDS);
+    });
+  });
+
+  describe("Albums", () => {
+    it("should return all albums with tracks by artist", async () => {
+      const { data } = await GET(
+        `/media/Albums?$filter=artist_ID eq 1&$expand=tracks`
+      );
+      expect(data).to.eql(ALL_ALBUMS_WITH_TRACKS_BY_ARTIST);
+    });
+  });
+
+  describe("Customers", () => {
+    it("should return customer with their invoices", async () => {
+      const { data } = await GET(`/media/Customers(1)?$expand=supportRep`);
+      expect(data).to.eql(CUSTOMER_WITH_THEIR_SUPPORT_REP);
+    });
+  });
+
+  describe("Playlists", () => {
+    it("should return playlist with their tracks", async () => {
+      const { data } = await GET(`/media/Customers(1)?$expand=supportRep`);
+      expect(data).to.eql(CUSTOMER_WITH_THEIR_SUPPORT_REP);
+    });
+  });
+
+  describe("Tracks", () => {
+    it("should return the number of tracks by album", async () => {
+      const { data } = await GET(
+        `/media/PlaylistTrack/$count?$filter=playlist_ID eq 8`
+      );
+      expect(data).to.eql(EIGHTH_ALBUM_TRACKS_COUNT);
+    });
+  });
+});
diff --git a/media-store/test/media-store.test.js b/media-store/test/media-store.test.js
deleted file mode 100644
index e69de29b..00000000
diff --git a/media-store/test/test.http b/media-store/test/test.http
index 3b07165c..f803da15 100644
--- a/media-store/test/test.http
+++ b/media-store/test/test.http
@@ -15,17 +15,19 @@ GET {{media-store-service}}/Artists
 ### ------------------------------------------------------------------------
 # Get Albums
 GET {{media-store-service}}/Albums
-?$expand=artist&$top=10
+?$filter=artist_ID eq 1
+&$expand=tracks,artist
+
 
 ### ------------------------------------------------------------------------
 # Get Customers
-GET {{media-store-service}}/Customers
-?$expand=supportRep&$top=10
+GET {{media-store-service}}/Customers(1)
+?$expand=supportRep
 
 ### ------------------------------------------------------------------------
 # Get Employees
-GET {{media-store-service}}/Employees
-?$expand=reportsTo&$top=10
+GET {{media-store-service}}/Employees(1)
+?$expand=subordinates,reportsTo
 
 ### ------------------------------------------------------------------------
 # Get Genres
@@ -49,8 +51,10 @@ GET {{media-store-service}}/MediaTypes
 
 ### ------------------------------------------------------------------------
 # Get PlaylistTrack
-GET {{media-store-service}}/PlaylistTrack
-?$top=10&$expand=track,playlist
+GET {{media-store-service}}/PlaylistTrack/$count
+?$filter=playlist_ID eq 8
+# ?$count=true
+# &$expand=track&$select=track
 
 ### ------------------------------------------------------------------------
 # Get Playlists
@@ -60,4 +64,4 @@ GET {{media-store-service}}/Playlists
 ### ------------------------------------------------------------------------
 # Get Playlists
 GET {{media-store-service}}/Tracks
-?$top=10&$expand=genre,mediaType,album
\ No newline at end of file
+# ?$top=10&$expand=genre,mediaType,album
\ No newline at end of file
diff --git a/media-store/util/importData.js b/media-store/util/importData.js
index a17f9163..6636d974 100644
--- a/media-store/util/importData.js
+++ b/media-store/util/importData.js
@@ -86,14 +86,18 @@ const logProcessArgs = () => {
       const { name: targetEntityName, elements } = targetCSNEntities[index];
       console.log(`[LOG]:  Processing ${targetEntityName}`);
       const targetColumns = elementsToColumns(elements); // e.g. ['ID', ..., 'total', 'customer_ID']
-      const insertQuery = constructInsertQuery(targetEntityName, targetColumns); // e.g. { INSERT: ... }
+      const insertQuery = constructInsertQuery(targetEntityName, targetColumns);
 
-      const srcEntityName = camelCaseToSnake(targetEntityName.split(".").pop()); // e.g. playlist_track
+      const srcEntityName = camelCaseToSnake(targetEntityName.split(".").pop());
       const srcResultRows = await srcStorage.read(srcEntityName); // e.g. [ { AlbumId:1, ArtistId:1, Title:'some' }, ... ]
-
       if (!srcResultRows || srcResultRows.length < ZERO_VALUE) {
+        console.log(
+          `[LOG] Skipping ${targetEntityName}. 
+          There is no data provided in ${SRC_STORAGE_NAME}, ${srcEntityName}`
+        );
         continue;
       }
+
       const srcColumns = Object.keys(srcResultRows[FIRST_INDEX]);
       const columns = reorderTargetColumns(srcColumns, targetColumns);
       if (new Set(columns).size !== columns.length) {