Practical No. 26
Uploaded by
sunnygaikwad4747Practical No. 26
Uploaded by
sunnygaikwad4747Practical No. 26: Perform Async task using SQLite.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="50sp"
android:layout_marginLeft="50dp"
>
<TextView
android:id="@+id/t1"
android:layout_width="266dp"
android:layout_height="wrap_content"
android:text="Student Details"
android:textSize="20sp" />
<EditText
android:id="@+id/Rollno"
android:layout_width="263dp"
android:layout_height="wrap_content"
android:layout_below="@+id/t1"
android:layout_marginTop="10dp"
android:hint="Enter Rollno:"
android:inputType="number"
android:textSize="20sp" />
<EditText
android:id="@+id/Name"
android:layout_width="266dp"
android:layout_height="wrap_content"
android:layout_below="@+id/Rollno"
android:layout_marginTop="10dp"
android:hint="Enter Name"
android:inputType="text"
android:textSize="20sp" />
<Button
android:id="@+id/Insert"
android:layout_width="125dp"
Prepared by Shivani S. Shinde
android:layout_height="wrap_content"
android:layout_below="@+id/Name"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp"
android:layout_marginRight="10dp"
android:onClick="insertData"
android:text="Add"
android:textSize="20dp" />
<Button
android:id="@+id/Delete"
android:layout_width="120dp"
android:layout_height="wrap_content"
android:text="Delete"
android:textSize="20dp"
android:onClick="deleteData"
android:layout_marginTop="10dp"
android:layout_below="@+id/Name"
android:layout_toRightOf="@id/Insert"
/>
<Button
android:id="@+id/Update"
android:layout_width="120dp"
android:layout_height="wrap_content"
android:layout_below="@+id/Name"
android:layout_marginLeft="-254dp"
android:layout_marginTop="72dp"
android:layout_toRightOf="@id/Delete"
android:onClick="updateData"
android:text="Update"
android:textSize="20dp" />
<Button
android:id="@+id/View"
android:layout_width="114dp"
android:layout_height="wrap_content"
android:layout_below="@+id/Delete"
android:layout_marginStart="19dp"
android:layout_marginTop="14dp"
Prepared by Shivani S. Shinde
android:layout_toEndOf="@+id/Update"
android:onClick="viewData"
android:text="View"
android:textSize="20dp" />
</RelativeLayout>
Java:
package com.example.sql;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity
{
EditText Rollno,Name;
SQLiteDatabase db;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState); setContentView(R.layout.activity_main);
Rollno=(EditText)findViewById(R.id.Rollno);
Name=(EditText)findViewById(R.id.Name);
db=openOrCreateDatabase("mydb", Context.MODE_PRIVATE, null);
//mydb" → The name of the database.
// Context.MODE_PRIVATE → The database is private to the application.
// null → No c`ustom CursorFactory is used.
db.execSQL("CREATE TABLE IF NOT EXISTS student(rollno VARCHAR,name
VARCHAR);");
}
public void insertData(View v){
Prepared by Shivani S. Shinde
db.execSQL("INSERT INTO student
VALUES('"+Rollno.getText()+"','"+Name.getText()+"');");
Toast.makeText(MainActivity.this,"Data Inserted",Toast.LENGTH_LONG).show();
}
public void deleteData(View v) {
db.execSQL("DELETE FROM student WHERE rollno='"+Rollno.getText()+"'");
Toast.makeText(MainActivity.this,"Data Deleted",Toast.LENGTH_LONG).show();
}
public void updateData(View v) {
db.execSQL("UPDATE student SET name='" + Name.getText() + "' WHERE
rollno='"+Rollno.getText()+"'");
Toast.makeText(MainActivity.this,"Data Updated",Toast.LENGTH_LONG).show();
}
public void viewData(View v) {
// Get rollno from input
String rollno = Rollno.getText().toString();
// Check for empty input
if (rollno.isEmpty()) {
Toast.makeText(this, "Please enter a roll number", Toast.LENGTH_SHORT).show();
return;
}
// Safe query using parameterized arguments
Cursor c = db.rawQuery("SELECT * FROM student WHERE rollno=?", new
String[]{rollno});
if (c.moveToFirst()) {
// Get data from cursor
String name = c.getString(1);
// Display in EditText
Name.setText(name);
// Show data in toast
Toast.makeText(this,
"Roll No: " + rollno + "\nName: " + name,
Toast.LENGTH_LONG).show();
} else {
Prepared by Shivani S. Shinde
Toast.makeText(this, "No student found with this roll number",
Toast.LENGTH_SHORT).show();
}
// Close cursor
c.close();
}
}