Question

我正在做一个项目，我需要从sqlite数据库中检索数据，但无法做到这一点。请帮助我完成。

我的登录代码

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 is not executing");
                    String[] args={"null"};
                    Cursor c=db.rawQuery("select * from login where mobile_no='"+mobile_no+"'",args);
                    c.moveToFirst();
                    show("not going inside");

                    if(c.getCount()>0)
                    {
                        show("Success fully 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();
    }

}

请仔细检查。我正在尝试从db检索数据并检查，但它没有执行操作。

Answer 1

如果您想从SQLite中检索数据以便登录，请使用以下代码：

#test:hover
{
    background-color: blue;
}

最后在SQLite数据库类中使用它：

 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 the Stored password matches with  Password entered by 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 you can do anything with 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 does 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 you can do anything with text*/
                toast.show();
            }
            editTextUserName.setText("");
            editTextID.setText("");
            editTextID.requestFocus();
        }
    }

Answer 2

您可以使用它从Sqlite中检索数据。

首先在需要检索数据的地方使用此代码：

 OurAppsPackages = new ArrayList<String>();
        OurAppsPackages = databaseHelper.getOurAllAppsPackage();

在数据库的B2MDatabaseHelper类中使用波纹管代码。

 public ArrayList<String> getOurAllAppsPackage() {
        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, null, null, null, null, null);
        cursor.moveToFirst();
        ArrayList<String> pkgs= new ArrayList<String>();

        if (cursor != null && cursor.getCount() > 0) {
            cursor.moveToFirst();
            for (int i = 0; i < cursor.getCount(); i++) {
                String pkgN = cursor.getString(cursor.getColumnIndex("PackageName"));
                pkgs.add(pkgN.toString());
                cursor.moveToNext();
            }
        }
        return pkgs;
    }

我无法从没有php或任何的sqlite中检索android中的数据库中的数据

2 个答案: