diff --git a/dao/src/main/java/com/iluwatar/App.java b/dao/src/main/java/com/iluwatar/App.java
index db4d417b2..dad5cc8ab 100644
--- a/dao/src/main/java/com/iluwatar/App.java
+++ b/dao/src/main/java/com/iluwatar/App.java
@@ -1,29 +1,118 @@
 package com.iluwatar;
 
+import java.util.List;
 
-
+/**
+ * 
+ * 
+ *
+ */
 public class App {
+	
     public static void main( String[] args ) {   
-    	WizardDaoImpl dao = new WizardDaoImpl();
-    	persistData(dao);
+    	initData();
     	queryData();
     }
     
-    public static void persistData(WizardDaoImpl dao) {
-    	Spell spell = new Spell("Fireball");
-    	Spellbook spellbook = new Spellbook("Book of fire");
-    	spell.setSpellbook(spellbook);
-    	spellbook.getSpells().add(spell);
-    	Wizard wizard = new Wizard("Jugga");
-    	spellbook.setWizard(wizard);
-    	wizard.getSpellbooks().add(spellbook);
-    	dao.persist(wizard);
+    public static void initData() {
+    	Spell spell1 = new Spell("Ice dart");
+    	Spell spell2 = new Spell("Invisibility");
+    	Spell spell3 = new Spell("Stun bolt");
+    	Spell spell4 = new Spell("Confusion");
+    	Spell spell5 = new Spell("Darkness");
+    	Spell spell6 = new Spell("Fireball");
+    	Spell spell7 = new Spell("Enchant weapon");
+    	Spell spell8 = new Spell("Rock armour");
+    	Spell spell9 = new Spell("Light");
+    	Spell spell10 = new Spell("Bee swarm");
+    	Spell spell11 = new Spell("Haste");
+    	Spell spell12 = new Spell("Levitation");
+    	Spell spell13 = new Spell("Magic lock");
+    	Spell spell14 = new Spell("Summon hell bat");
+    	Spell spell15 = new Spell("Water walking");
+    	Spell spell16 = new Spell("Magic storm");
+    	Spell spell17 = new Spell("Entangle");
+    	SpellDao spellDao = new SpellDaoImpl();
+    	spellDao.persist(spell1);
+    	spellDao.persist(spell2);
+    	spellDao.persist(spell3);
+    	spellDao.persist(spell4);
+    	spellDao.persist(spell5);
+    	spellDao.persist(spell6);
+    	spellDao.persist(spell7);
+    	spellDao.persist(spell8);
+    	spellDao.persist(spell9);
+    	spellDao.persist(spell10);
+    	spellDao.persist(spell11);
+    	spellDao.persist(spell12);
+    	spellDao.persist(spell13);
+    	spellDao.persist(spell14);
+    	spellDao.persist(spell15);
+    	spellDao.persist(spell16);
+    	spellDao.persist(spell17);
+    	
+    	SpellbookDao spellbookDao = new SpellbookDaoImpl();
+    	Spellbook spellbook1 = new Spellbook("Book of Orgymon");
+    	spellbookDao.persist(spellbook1);
+    	spellbook1.addSpell(spell1);
+    	spellbook1.addSpell(spell2);
+    	spellbook1.addSpell(spell3);    	
+    	spellbook1.addSpell(spell4);    
+    	spellbookDao.merge(spellbook1);
+    	Spellbook spellbook2 = new Spellbook("Book of Aras");
+    	spellbookDao.persist(spellbook2);
+    	spellbook2.addSpell(spell5);
+    	spellbook2.addSpell(spell6);    	
+    	spellbookDao.merge(spellbook2);
+    	Spellbook spellbook3 = new Spellbook("Book of Kritior");
+    	spellbookDao.persist(spellbook3);
+    	spellbook3.addSpell(spell7);
+    	spellbook3.addSpell(spell8);
+    	spellbook3.addSpell(spell9);    	
+    	spellbookDao.merge(spellbook3);
+    	Spellbook spellbook4 = new Spellbook("Book of Tamaex");
+    	spellbookDao.persist(spellbook4);
+    	spellbook4.addSpell(spell10);
+    	spellbook4.addSpell(spell11);
+    	spellbook4.addSpell(spell12);    	
+    	spellbookDao.merge(spellbook4);
+    	Spellbook spellbook5 = new Spellbook("Book of Idores");
+    	spellbookDao.persist(spellbook5);
+    	spellbook5.addSpell(spell13);
+    	spellbookDao.merge(spellbook5);
+    	Spellbook spellbook6 = new Spellbook("Book of Opaen");
+    	spellbookDao.persist(spellbook6);
+    	spellbook6.addSpell(spell14);
+    	spellbook6.addSpell(spell15);    	
+    	spellbookDao.merge(spellbook6);
+    	Spellbook spellbook7 = new Spellbook("Book of Kihione");
+    	spellbookDao.persist(spellbook7);
+    	spellbook7.addSpell(spell16);
+    	spellbook7.addSpell(spell17);
+    	spellbookDao.merge(spellbook7);
+    	
+    	WizardDao wizardDao = new WizardDaoImpl();
+    	Wizard wizard1 = new Wizard("Aderlard Boud");
+    	wizardDao.persist(wizard1);
+//    	wizard1.addSpellbook(spellbook1);
+//    	wizard1.addSpellbook(spellbook2);
+    	wizardDao.merge(wizard1);
+    	Wizard wizard2 = new Wizard("Anaxis Bajraktari");
+    	wizardDao.persist(wizard2);
+//    	wizard2.addSpellbook(spellbook3);
+//    	wizard2.addSpellbook(spellbook4);
+    	wizardDao.merge(wizard2);
+    	Wizard wizard3 = new Wizard("Xuban Munoa");
+    	wizardDao.persist(wizard3);
+//    	wizard3.addSpellbook(spellbook5);
+//    	wizard3.addSpellbook(spellbook6);
+    	wizardDao.merge(wizard3);
+    	Wizard wizard4 = new Wizard("Blasius Dehooge");
+    	wizardDao.persist(wizard4);
+//    	wizard4.addSpellbook(spellbook7);
+    	wizardDao.merge(wizard4);
     }
     
     public static void queryData() {
-    	MagicService magicService = new MagicServiceImpl();
-    	for (Wizard w: magicService.findAllWizards()) {
-    		System.out.println(w);
-    	}
     }
 }
diff --git a/dao/src/main/java/com/iluwatar/MagicService.java b/dao/src/main/java/com/iluwatar/MagicService.java
index c02c23ecb..296ace83c 100644
--- a/dao/src/main/java/com/iluwatar/MagicService.java
+++ b/dao/src/main/java/com/iluwatar/MagicService.java
@@ -1,13 +1,6 @@
 package com.iluwatar;
 
-import java.util.List;
 
 public interface MagicService {
-
-	List<Wizard> findAllWizards();
-
-	List<Spellbook> findAllSpellbooks();
-	
-	List<Spell> findAllSpells();
 	
 }
diff --git a/dao/src/main/java/com/iluwatar/MagicServiceImpl.java b/dao/src/main/java/com/iluwatar/MagicServiceImpl.java
index 8fbd0d6e4..f7fce36ba 100644
--- a/dao/src/main/java/com/iluwatar/MagicServiceImpl.java
+++ b/dao/src/main/java/com/iluwatar/MagicServiceImpl.java
@@ -1,21 +1,5 @@
 package com.iluwatar;
 
-import java.util.List;
-
 public class MagicServiceImpl implements MagicService {
 
-	@Override
-	public List<Wizard> findAllWizards() {
-		return new WizardDaoImpl().findAll();
-	}
-
-	@Override
-	public List<Spellbook> findAllSpellbooks() {
-		return new SpellbookDaoImpl().findAll();
-	}
-
-	@Override
-	public List<Spell> findAllSpells() {
-		return new SpellDaoImpl().findAll();
-	}
 }
diff --git a/dao/src/main/java/com/iluwatar/SpellDao.java b/dao/src/main/java/com/iluwatar/SpellDao.java
new file mode 100644
index 000000000..b7c57f43e
--- /dev/null
+++ b/dao/src/main/java/com/iluwatar/SpellDao.java
@@ -0,0 +1,5 @@
+package com.iluwatar;
+
+public interface SpellDao extends Dao<Spell> {
+
+}
diff --git a/dao/src/main/java/com/iluwatar/SpellDaoImpl.java b/dao/src/main/java/com/iluwatar/SpellDaoImpl.java
index 77e6872bd..be898dbc0 100644
--- a/dao/src/main/java/com/iluwatar/SpellDaoImpl.java
+++ b/dao/src/main/java/com/iluwatar/SpellDaoImpl.java
@@ -1,5 +1,5 @@
 package com.iluwatar;
 
-public class SpellDaoImpl extends DaoBaseImpl<Spell> {
+public class SpellDaoImpl extends DaoBaseImpl<Spell> implements SpellDao {
 
 }
diff --git a/dao/src/main/java/com/iluwatar/Spellbook.java b/dao/src/main/java/com/iluwatar/Spellbook.java
index fbd490e70..e3fc4b37f 100644
--- a/dao/src/main/java/com/iluwatar/Spellbook.java
+++ b/dao/src/main/java/com/iluwatar/Spellbook.java
@@ -6,11 +6,9 @@ import java.util.Set;
 import javax.persistence.CascadeType;
 import javax.persistence.Column;
 import javax.persistence.Entity;
-import javax.persistence.FetchType;
 import javax.persistence.GeneratedValue;
 import javax.persistence.Id;
-import javax.persistence.JoinColumn;
-import javax.persistence.ManyToOne;
+import javax.persistence.ManyToMany;
 import javax.persistence.OneToMany;
 import javax.persistence.Table;
 
@@ -20,6 +18,7 @@ public class Spellbook extends BaseEntity {
 	
 	public Spellbook() {
 		spells = new HashSet<Spell>();
+		wizards = new HashSet<Wizard>();
 	}
 	
 	public Spellbook(String name) {
@@ -42,11 +41,10 @@ public class Spellbook extends BaseEntity {
 	
 	private String name;
 
-	@ManyToOne
-	@JoinColumn(name="WIZARD_ID_FK", referencedColumnName="WIZARD_ID")
-	private Wizard wizard;
+	@ManyToMany(mappedBy = "spellbooks")
+	private Set<Wizard> wizards;
 
-	@OneToMany(mappedBy = "spellbook", orphanRemoval = true, fetch = FetchType.LAZY, cascade = CascadeType.ALL)
+	@OneToMany(mappedBy = "spellbook", orphanRemoval = true, cascade = CascadeType.ALL)
 	private Set<Spell> spells;
 	
 	public String getName() {
@@ -57,12 +55,12 @@ public class Spellbook extends BaseEntity {
 		this.name = name;
 	}
 
-	public Wizard getWizard() {
-		return wizard;
+	public Set<Wizard> getWizards() {
+		return wizards;
 	}
 
-	public void setWizard(Wizard wizard) {
-		this.wizard = wizard;
+	public void setWizards(Set<Wizard> wizards) {
+		this.wizards = wizards;
 	}
 
 	public Set<Spell> getSpells() {
@@ -72,6 +70,11 @@ public class Spellbook extends BaseEntity {
 	public void setSpells(Set<Spell> spells) {
 		this.spells = spells;
 	}
+
+	public void addSpell(Spell spell) {
+		spell.setSpellbook(this);
+		spells.add(spell);
+	}
 	
 	@Override
 	public String toString() {
diff --git a/dao/src/main/java/com/iluwatar/SpellbookDao.java b/dao/src/main/java/com/iluwatar/SpellbookDao.java
new file mode 100644
index 000000000..e6e7f7d54
--- /dev/null
+++ b/dao/src/main/java/com/iluwatar/SpellbookDao.java
@@ -0,0 +1,5 @@
+package com.iluwatar;
+
+public interface SpellbookDao extends Dao<Spellbook> {
+
+}
diff --git a/dao/src/main/java/com/iluwatar/SpellbookDaoImpl.java b/dao/src/main/java/com/iluwatar/SpellbookDaoImpl.java
index e1c6fd6f6..3d128e546 100644
--- a/dao/src/main/java/com/iluwatar/SpellbookDaoImpl.java
+++ b/dao/src/main/java/com/iluwatar/SpellbookDaoImpl.java
@@ -1,5 +1,5 @@
 package com.iluwatar;
 
-public class SpellbookDaoImpl extends DaoBaseImpl<Spellbook> {
+public class SpellbookDaoImpl extends DaoBaseImpl<Spellbook> implements SpellbookDao {
 
 }
diff --git a/dao/src/main/java/com/iluwatar/Wizard.java b/dao/src/main/java/com/iluwatar/Wizard.java
index bd8481f15..d7d91f4fc 100644
--- a/dao/src/main/java/com/iluwatar/Wizard.java
+++ b/dao/src/main/java/com/iluwatar/Wizard.java
@@ -6,10 +6,9 @@ import java.util.Set;
 import javax.persistence.CascadeType;
 import javax.persistence.Column;
 import javax.persistence.Entity;
-import javax.persistence.FetchType;
 import javax.persistence.GeneratedValue;
 import javax.persistence.Id;
-import javax.persistence.OneToMany;
+import javax.persistence.ManyToMany;
 import javax.persistence.Table;
 
 @Entity
@@ -40,7 +39,7 @@ public class Wizard extends BaseEntity {
 	
 	private String name;
 
-	@OneToMany(mappedBy = "wizard", orphanRemoval = true, fetch = FetchType.LAZY, cascade = CascadeType.ALL)
+	@ManyToMany(cascade = CascadeType.ALL)
 	private Set<Spellbook> spellbooks;
 	
 	public String getFirstName() {
@@ -59,6 +58,11 @@ public class Wizard extends BaseEntity {
 		this.spellbooks = spellbooks;
 	}
 
+	public void addSpellbook(Spellbook spellbook) {
+		spellbook.getWizards().add(this);
+		spellbooks.add(spellbook);
+	}
+	
 	@Override
 	public String toString() {
 		return name;
diff --git a/dao/src/main/java/com/iluwatar/WizardDao.java b/dao/src/main/java/com/iluwatar/WizardDao.java
new file mode 100644
index 000000000..687ceca42
--- /dev/null
+++ b/dao/src/main/java/com/iluwatar/WizardDao.java
@@ -0,0 +1,5 @@
+package com.iluwatar;
+
+public interface WizardDao extends Dao<Wizard> {
+
+}
diff --git a/dao/src/main/java/com/iluwatar/WizardDaoImpl.java b/dao/src/main/java/com/iluwatar/WizardDaoImpl.java
index 58d61216b..2a8df6479 100644
--- a/dao/src/main/java/com/iluwatar/WizardDaoImpl.java
+++ b/dao/src/main/java/com/iluwatar/WizardDaoImpl.java
@@ -1,5 +1,5 @@
 package com.iluwatar;
 
-public class WizardDaoImpl extends DaoBaseImpl<Wizard> {
+public class WizardDaoImpl extends DaoBaseImpl<Wizard> implements WizardDao {
 
 }