I am unable to retrieve data from database in android from sqlite without php or any -

i doing project, need retrieve data sqlite database, unable that. kindly me through out.

my login code

package com.example.pallavi.myproject;  import android.app.activity; import android.content.intent; import android.database.cursor; import android.database.sqlite.sqlitedatabase; import android.os.bundle; import android.text.inputtype; import android.view.view; import android.widget.edittext; import android.widget.imageview; import android.widget.toast;   public class login extends activity{     intent i=null;      edittext tv1,tv4;     boolean flag=false;     sqlitedatabase db=null;     @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.login);          tv1 = (edittext) findviewbyid(r.id.phone2);         tv4 = (edittext) findviewbyid(r.id.password2);         db = openorcreatedatabase("mydb", mode_private, null);             }     public void action(view v)     {                  string mobile_no=tv1.gettext().tostring();                 string password=tv4.gettext().tostring();                /*  if(mobile_no==null||mobile_no=="")                 {                     show("please enter correct mobile number.");                 }                 else if(password==null||password=="")                 {                     show("please enter correct password.");                 }                 else*/                 {                       show("query not executing");                     string[] args={"null"};                     cursor c=db.rawquery("select * login mobile_no='"+mobile_no+"'",args);                     c.movetofirst();                     show("not going inside");                      if(c.getcount()>0)                     {                         show("success login");                         i=new intent(this,post.class);                          db.close();                         finish();                     }                     else                         show("wrong password or mobile number.");                  }          }     public void acc(view v)     {         if (v.getid()==r.id.button)         {              intent i=new intent(login.this,mainactivity.class);             startactivity(i);         }     }      @override      protected void onactivityresult(int requestcode, int resultcode, intent data) {      }      public void show(string str)     {         toast.maketext(this, str, toast.length_long).show();     }  } 

kindly check through it. trying retrieve data db , check, not performing operation.

if want retrieve data sqlite log in use code:

 public void login_user(view view) {          edittextusername = (edittext) findviewbyid(r.id.edittext2);         edittextid = (edittext) findviewbyid(r.id.edittext);         edittextid.setfocusable(true);          username = edittextusername.gettext().tostring();         password = edittextid.gettext().tostring();          final string idd = password;         final string name = username;          if (password.equals("")) {             edittextid.seterror("enter user id");             edittextid.requestfocus();         } else if (username.equals("")) {             edittextusername.seterror("enter user name");             edittextusername.requestfocus();         } else {             string storedpassword = databasehelper.getsinuserlgeentry(username,password);             // check if stored password matches  password entered user             if (password.equals(storedpassword)) {                 toast toast = toast.maketext(this, "congrats: login successful", toast.length_long);                 view vieew = toast.getview();                 //  vieew.setbackgroundcolor(color.parsecolor("#bd8bdc"));                 vieew.setbackgroundresource(r.drawable.textinputborder);                 toast.setview(vieew);                 //  textview text = (textview) view.findviewbyid(android.r.id.message);                 /*here can text*/                 toast.show();                 intent intent = new intent(this, user_home.class);                 intent.putextra("name", username);                 intent.putextra("id", password);                 startactivity(intent);              } else {                 toast toast = toast.maketext(this, "user name or password not match", toast.length_long);                 view vieew = toast.getview();                 //  vieew.setbackgroundcolor(color.parsecolor("#bd8bdc"));                 vieew.setbackgroundresource(r.drawable.textinputborder);                 toast.setview(vieew);                 //  textview text = (textview) view.findviewbyid(android.r.id.message);                 /*here can text*/                 toast.show();             }             edittextusername.settext("");             edittextid.settext("");             edittextid.requestfocus();         }     } 

finally use in sqlite database class :

  public string getsinuserlgeentry(string username, string id) {         sqlitedatabase db = this.getwritabledatabase();         // cursor cursor = db.query("day_info", null, " emp_name=?", new string[]{username}, null, null, null);         cursor cursor = db.query(table_name, null, emp_name + " '%" + username + "%' , " + main_idd + " '%" + id + "%'", null, null, null, null);         if (cursor.getcount() < 1) // username not exist         {             cursor.close();             return "not exist";         }         cursor.movetofirst();         string iddd = cursor.getstring(cursor.getcolumnindex("mid"));         cursor.close();         return iddd;     }