In this tutorial how to perform select operation in SQLite Database from \u00a0an Android Application is shown.<\/p>\n
Code:<\/p>\n
activity_main.xml<\/p>\n
<RelativeLayout xmlns:android=”http:\/\/schemas.android.com\/apk\/res\/android”
\nxmlns:tools=”http:\/\/schemas.android.com\/tools”
\nandroid:layout_width=”match_parent”
\nandroid:layout_height=”match_parent”
\nandroid:paddingBottom=”@dimen\/activity_vertical_margin”
\nandroid:paddingLeft=”@dimen\/activity_horizontal_margin”
\nandroid:paddingRight=”@dimen\/activity_horizontal_margin”
\nandroid:paddingTop=”@dimen\/activity_vertical_margin”
\ntools:context=”.MainActivity” ><\/p>\n
<TextView
\nandroid:id=”@+id\/textView1″
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_alignParentTop=”true”
\nandroid:layout_centerHorizontal=”true”
\nandroid:layout_marginTop=”50dp”
\nandroid:text=”Student Details” \/><\/p>\n
<EditText
\nandroid:id=”@+id\/editRollno”
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_below=”@+id\/textView1″
\nandroid:layout_centerHorizontal=”true”
\nandroid:layout_marginTop=”29dp”
\nandroid:ems=”10″
\nandroid:hint=”Enter Roll No” ><\/p>\n
<requestFocus \/>
\n<\/EditText><\/p>\n
<EditText
\nandroid:id=”@+id\/editMarks”
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_below=”@+id\/editName”
\nandroid:layout_centerHorizontal=”true”
\nandroid:layout_marginTop=”34dp”
\nandroid:ems=”10″
\nandroid:hint=”Enter Marks” \/><\/p>\n
<EditText
\nandroid:id=”@+id\/editName”
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_alignLeft=”@+id\/editRollno”
\nandroid:layout_below=”@+id\/editRollno”
\nandroid:layout_marginTop=”28dp”
\nandroid:ems=”10″
\nandroid:hint=”Enter Name” \/><\/p>\n
<Button
\nandroid:id=”@+id\/btnView”
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_alignLeft=”@+id\/btnAdd”
\nandroid:layout_below=”@+id\/btnAdd”
\nandroid:layout_marginTop=”20dp”
\nandroid:onClick=”dbFunction”
\nandroid:text=”View” \/><\/p>\n
<Button
\nandroid:id=”@+id\/btnViewAll”
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_alignBaseline=”@+id\/btnView”
\nandroid:layout_alignBottom=”@+id\/btnView”
\nandroid:layout_alignRight=”@+id\/btnModify”
\nandroid:onClick=”dbFunction”
\nandroid:text=”View All” \/><\/p>\n
<Button
\nandroid:id=”@+id\/btnReset”
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_alignBottom=”@+id\/btnViewAll”
\nandroid:layout_alignRight=”@+id\/btnDelete”
\nandroid:onClick=”onReset”
\nandroid:text=”Reset” \/><\/p>\n
<\/RelativeLayout><\/p>\n
MainActivity.java<\/p>\n
package com.example.demo;<\/p>\n
import android.os.Bundle;
\nimport android.app.Activity;
\nimport android.app.AlertDialog.Builder;
\nimport android.content.Context;
\nimport android.database.Cursor;
\nimport android.database.sqlite.SQLiteDatabase;
\nimport android.view.Menu;
\nimport android.view.View;
\nimport android.widget.Button;
\nimport android.widget.EditText;<\/p>\n
public class MainActivity extends Activity{<\/p>\n
SQLiteDatabase db;
\nEditText editRollno,editName,editMarks;
\nButton btnAdd,btnModify,btnDelete,btnView,btnViewAll;<\/p>\n
@Override
\nprotected void onCreate(Bundle savedInstanceState) {
\nsuper.onCreate(savedInstanceState);
\nsetContentView(R.layout.activity_main);<\/p>\n
db=openOrCreateDatabase(“StudDB”,Context.MODE_PRIVATE,null);
\ndb.execSQL(“CREATE TABLE IF NOT EXISTS student(rollno VARCHAR,name VARCHAR,marks VARCHAR);”);<\/p>\n
editRollno=(EditText)findViewById(R.id.editRollno);
\neditName=(EditText)findViewById(R.id.editName);
\neditMarks=(EditText)findViewById(R.id.editMarks);
\nbtnAdd=(Button)findViewById(R.id.btnAdd);
\n}<\/p>\n
public void dbFunction(View view)
\n{
\nif(view==btnView)
\n{
\nif(editRollno.getText().toString().trim().length()==0)
\n{
\nshowMessage(“Error”,”Please enter Roll No”);
\nreturn;
\n}
\nelse
\n{
\nCursor c=db.rawQuery(“SELECT * FROM student WHERE rollno='”+editRollno.getText()+”‘”,null);
\nif(c.moveToFirst())
\n{
\neditName.setText(c.getString(1));
\neditMarks.setText(c.getString(2));
\n}
\nelse
\n{
\nshowMessage(“Error”,”Invalid Roll No”);
\nclearText();
\n}
\n}
\n}
\nif(view==btnViewAll)
\n{
\nCursor c=db.rawQuery(“SELECT * FROM student”, null);
\nif(c.getCount()==0)
\n{
\nshowMessage(“Error”,”No records found”);
\nreturn;
\n}
\nelse
\n{
\nStringBuffer buffer=new StringBuffer();
\nwhile(c.moveToNext())
\n{
\nbuffer.append(“Roll No: “+c.getString(0)+”\\n”);
\nbuffer.append(“Name: “+c.getString(1)+”\\n”);
\nbuffer.append(“Marks: “+c.getString(2)+”\\n\\n”);
\n}
\nshowMessage(“Student Details”,buffer.toString());
\n}
\n}
\n}<\/p>\n
public void showMessage(String title,String message)
\n{
\nBuilder builder=new Builder(this);
\nbuilder.setCancelable(true);
\nbuilder.setTitle(title);
\nbuilder.setMessage(message);
\nbuilder.show();
\n}<\/p>\n
public void clearText()
\n{
\neditRollno.setText(“”);
\neditName.setText(“”);
\neditMarks.setText(“”);
\neditRollno.requestFocus();
\n}<\/p>\n
public void onReset(View v)
\n{
\neditRollno.setText(“”);
\neditName.setText(“”);
\neditMarks.setText(“”);
\neditRollno.requestFocus();
\n}<\/p>\n
@Override
\npublic boolean onCreateOptionsMenu(Menu menu) {
\n\/\/Inflate the menu; this adds items to the action bar if it is present.
\ngetMenuInflater().inflate(R.menu.main, menu);
\nreturn true;
\n}
\n}<\/p>\n