I am trying to add single name in SQLite database of android , butt it adds multiple entries with same name

Hello everyone !

Dear all, I am trying to add one contact in database of android butt it add multiple entries with same name, kindly help me out as I am new in this filed. Thanks in advance for helping me out.

//Function to add single name/group name in database class
    public void createGroup(GroupsDetail gd){
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        // put values in database
       values.put(group_NAME , gd.getName());
       db.insert(table_Group , null , values);
       // close database transaction
       db.close();
}

//Function to get all names/group names in database class
   public List<GroupsDetail> getallcontacts(){
       List<GroupsDetail> groupList = new ArrayList<GroupsDetail>();
       String query = "SELECT * From " + table_Group;
       //get referance of ContactAS database
       SQLiteDatabase db = this.getWritableDatabase();
       Cursor cursor = db.rawQuery(query, null);
       GroupsDetail group = null;
       if(cursor.moveToFirst()){
        do{
            group = new GroupsDetail();
            group.setId(Integer.parseInt(cursor.getString(0)));
            group.setName(cursor.getString(1));
            groupList.add(group);
          }while(cursor.moveToNext());  
    }

    return groupList;   
}

//Code of main class 
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.widget.ArrayAdapter; 
import android.widget.Button;
import android.widget.ListView;

 public class Groups extends Activity{
 Button Addgroup,Delgroup;
 ListView groupnames;
 GroupsDetail gd;
 ArrayList<String> listItems;
 List<GroupsDetail> gdlist;
 Groupsdb gdb;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.groups);

    Addgroup = (Button)findViewById(R.id.addgroup);
    Delgroup = (Button)findViewById(R.id.deletegroup);
    groupnames = (ListView)findViewById(R.id.listofgroups);
    groupnames.setLongClickable(true);

    gdb = new Groupsdb(this);
    listItems = new ArrayList<String>();
    gdlist = new ArrayList<GroupsDetail>();

    gd = new GroupsDetail("Family");

    gdb.createGroup(gd);
    gdlist = gdb.getallcontacts();

    for(GroupsDetail cn : gdlist){
        listItems.add(cn.getName());
    }

    ArrayAdapter<String> adapter = new ArrayAdapter<String>(getApplicationContext(), R.layout.text, listItems);
    groupnames.setAdapter(adapter);

     }

}

 //code of GroupDetails class

  public class GroupsDetail {

        private String Name;
        private int id;

public GroupsDetail(){}

public GroupsDetail(String name){
    super();
    this.Name = name;
}

public GroupsDetail(String name, int i){
    super();
    this.Name = name;
    this.id = i;    
}

public int getId(){
    return id;
}

public void setId(int i){
   this.id = i; 
}

public String getName(){
    return Name;
}

public void setName(String name){
    this.Name = name;
}

  public String toString(){
    return "Group [id = " + id + ", Name = "+ Name + "]";  
      }
}