Sqlite Example in Kotlin

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp"
    android:id="@+id/main">

    <!-- EditText for Name -->
    <EditText
        android:id="@+id/editName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Enter Name"
        android:inputType="textPersonName"
        android:textSize="16sp"
        android:padding="10dp" />

    <!-- EditText for Location -->
    <EditText
        android:id="@+id/editLocation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Enter Location"
        android:inputType="text"
        android:textSize="16sp"
        android:padding="10dp" />

    <!-- EditText for Designation -->
    <EditText
        android:id="@+id/editDesignation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Enter Designation"
        android:inputType="text"
        android:textSize="16sp"
        android:padding="10dp" />

    <!-- Save Button -->
    <Button
        android:id="@+id/btnSave"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Save"
        android:textSize="18sp"
        android:padding="12dp"
        android:layout_marginTop="20dp"
        android:background="@android:color/holo_blue_light" />

</LinearLayout>
</layout>

MainActivity.kt

package com.androindian.sqlite

import android.content.Intent
import android.os.Bundle
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import androidx.databinding.DataBindingUtil
import com.androindian.sqlite.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    var binding: ActivityMainBinding?=null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        binding= DataBindingUtil.setContentView(this,R.layout.activity_main)
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }

        var dbhelper=DbHelper(this@MainActivity)

        binding?.btnSave?.setOnClickListener{
            var name=binding?.editName?.text?.toString()
            var location=binding?.editLocation?.text.toString()
            var designation=binding?.editDesignation?.text.toString()

            dbhelper.insertUserDetails(name,location,designation)
            Toast.makeText(this@MainActivity,"Saved Sucessfully",Toast.LENGTH_LONG).show()

            var intent=Intent(this@MainActivity,DetailsActivity::class.java)
            startActivity(intent)
        }
    }
}

Dbhelper.kt

package com.androindian.sqlite

import android.annotation.SuppressLint
import android.content.ContentValues
import android.content.Context
import android.database.Cursor
import android.database.sqlite.SQLiteDatabase
import android.database.sqlite.SQLiteOpenHelper



class DbHelper(context: Context?) : SQLiteOpenHelper(context, DB_NAME, null, DB_VERSION) {
    override fun onCreate(db: SQLiteDatabase) {
        val CREATE_TABLE = ("CREATE TABLE " + TABLE_Users + "("
                + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," + KEY_NAME + " TEXT,"
                + KEY_LOC + " TEXT,"
                + KEY_DESG + " TEXT" + ")")
        db.execSQL(CREATE_TABLE)
    }

    override fun onUpgrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
        // Drop older table if exist
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_Users)
        // Create tables again
        onCreate(db)
    }

    // **** CRUD (Create, Read, Update, Delete) Operations ***** //
    // Adding new User Details
    fun insertUserDetails(name: String?, location: String?, designation: String?) {
        //Get the Data Repository in write mode
        val db = this.writableDatabase
        //Create a new map of values, where column names are the keys
        val cValues = ContentValues()
        cValues.put(KEY_NAME, name)
        cValues.put(KEY_LOC, location)
        cValues.put(KEY_DESG, designation)
        // Insert the new row, returning the primary key value of the new row
        val newRowId = db.insert(TABLE_Users, null, cValues)
        db.close()
    }

    // Get User Details
    @SuppressLint("Range")
    fun GetUsers(): ArrayList<HashMap<String, String>> {
        val db = this.writableDatabase
        val userList = ArrayList<HashMap<String, String>>()
        val query = "SELECT name, location, designation FROM " + TABLE_Users
        val cursor = db.rawQuery(query, null)
        while (cursor.moveToNext()) {
            val user = HashMap<String, String>()
            user["name"] = cursor.getString(cursor.getColumnIndex(KEY_NAME))
            user["designation"] = cursor.getString(cursor.getColumnIndex(KEY_DESG))
            user["location"] = cursor.getString(cursor.getColumnIndex(KEY_LOC))
            userList.add(user)
        }
        return userList
    }

    // Get User Details based on userid
    @SuppressLint("Range")
    fun GetUserByUserId(userid: Int): ArrayList<HashMap<String, String>> {
        val db = this.writableDatabase
        val userList = ArrayList<HashMap<String, String>>()
        val query = "SELECT name, location, designation FROM " + TABLE_Users
        val cursor = db.query(
            TABLE_Users,
            arrayOf(KEY_NAME, KEY_LOC, KEY_DESG),
            KEY_ID + "=?",
            arrayOf(userid.toString()),
            null,
            null,
            null,
            null
        )
        if (cursor.moveToNext()) {
            val user = HashMap<String, String>()
            user["name"] = cursor.getString(cursor.getColumnIndex(KEY_NAME))
            user["designation"] = cursor.getString(cursor.getColumnIndex(KEY_DESG))
            user["location"] = cursor.getString(cursor.getColumnIndex(KEY_LOC))
            userList.add(user)
        }
        return userList
    }

    // Delete User Details
    fun DeleteUser(userid: Int) {
        val db = this.writableDatabase
        db.delete(TABLE_Users, KEY_ID + " = ?", arrayOf(userid.toString()))
        db.close()
    }

    // Update User Details
    fun UpdateUserDetails(
        location: String?,
        designation: String?,
        id: Int
    ): Int {
        val db = this.writableDatabase
        val cVals = ContentValues()
        cVals.put(KEY_LOC, location)
        cVals.put(KEY_DESG, designation)
        return db.update(TABLE_Users, cVals, "$KEY_ID = ?", arrayOf(id.toString()))
    }

    companion object {
        private const val DB_VERSION = 1
        private const val DB_NAME = "usersdb"
        private const val TABLE_Users = "userdetails"
        private const val KEY_ID = "id"
        private const val KEY_NAME = "name"
        private const val KEY_LOC = "location"
        private const val KEY_DESG = "designation"
    }
}

activity_data.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".DetailsActivity"
    android:orientation="vertical">


    <ListView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/list"
        android:layout_margin="10dp"/>

</LinearLayout>
</layout>

DeatilsActivity.kt

package com.androindian.sqlite

import android.os.Bundle
import android.widget.SimpleAdapter
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import androidx.databinding.DataBindingUtil
import androidx.recyclerview.widget.ListAdapter
import com.androindian.sqlite.databinding.ActivityDetailsBinding

class DetailsActivity : AppCompatActivity() {
    var binding:ActivityDetailsBinding?=null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        binding= DataBindingUtil.setContentView(this,R.layout.activity_details)
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }
        var dbHelper=DbHelper(this@DetailsActivity)

        var uselist=dbHelper.GetUsers()

        val adapter: android.widget.ListAdapter = SimpleAdapter(
            this@DetailsActivity,
            uselist,
            R.layout.custom,
            arrayOf("name", "designation", "location"),
            intArrayOf(R.id.name, R.id.designation, R.id.location))
        binding?.list?.adapter=adapter
    }
}

custom.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/name"
        android:layout_margin="10dp"/>
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/location"
        android:layout_margin="10dp"/>
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/designation"
        android:layout_margin="10dp"/>

</LinearLayout>