How To Create A Database In Android Sqlite Tutorial
Android SQLite Database Tutorial with Examples
- What is SQLite?
- The contents of this example
- The steps for working with SQLite Database
- Create a project and design the interface
- Java Code
1- What is SQLite?
SQLite is a relational database, open source, it is built on the Android operating system, so you can use it any time, and without any further configuration.
Generally with databases such as Oracle, MySQL, .. you need a Driver libary, and create JDBC connection, however with SQLite it is not necessary.
2- The contents of this example
Assume that you create an application that runs on your Android device, the app records the notes in your day. You need a table structure to store the notes.
- Name of the table: Note
Column Name | Data Type | Constraint | Description |
Note_Id | int | Primary Key | Primary Key |
Note_Title | text | Note title | |
Note_Content | text | Content |
Preview the example:
3- The steps for working with SQLite Database
You need to create a utility class for working with SQLite database, this class should extends from SQLiteOpenHelper class. There are two important methods you need to override it is onCreate() and onUpgrade().
- Create MyDatabaseHelper class extends from SQLiteOpenHelper.
- After extending your class from SQLiteOpenHelper you need to override two methods onCreate() and onUpgrage()
- onCreate() – These is where you need to write create table statements. This is called when database is created.
- onUpgrade() – This method is called when database is upgraded like modifying the table structure, adding constraints to database etc.,
MyDatabaseHelper.java
public class MyDatabaseHelper extends SQLiteOpenHelper { // .... public MyDatabaseHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); } @Override public void onCreate(SQLiteDatabase db) { // Script to create table. String script = "CREATE TABLE " + TABLE_NOTE + "(" + COLUMN_NOTE_ID + " INTEGER PRIMARY KEY," + COLUMN_NOTE_TITLE + " TEXT," + COLUMN_NOTE_CONTENT + " TEXT" + ")"; // Execute script. db.execSQL(script); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // Drop table db.execSQL("DROP TABLE IF EXISTS " + TABLE_NOTE); // Recreate onCreate(db); } // ... }
4- Create a project and design the interface
Create an "Empty Activity" project named SQLiteDemo to practice this example.
- Name: SQLiteDemo
- Package name: org.o7planning.sqlitedemo
Create an Empty Activity.
- File/New/Activity/Empty Activity
Enter:
- Activity Name: AddEditNoteActivity
- (Check Generate Layout File)
- Layout: activity_add_edit_note
- Package name: org.o7planning.sqlitedemo
activity_main.xml
activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout 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:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <ListView android:id="@+id/listView" android:layout_width="0dp" android:layout_height="0dp" android:layout_marginStart="16dp" android:layout_marginLeft="16dp" android:layout_marginTop="16dp" android:layout_marginEnd="16dp" android:layout_marginRight="16dp" android:layout_marginBottom="16dp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" /> </androidx.constraintlayout.widget.ConstraintLayout>
activity_add_edit_note.xml
Set ID, Text for components on the interface:
activity_add_edit_note.xml
<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout 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:layout_width="match_parent" android:layout_height="match_parent" tools:context=".AddEditNoteActivity"> <EditText android:id="@+id/editText_note_title" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginStart="16dp" android:layout_marginLeft="16dp" android:layout_marginTop="16dp" android:layout_marginEnd="16dp" android:layout_marginRight="16dp" android:ems="10" android:inputType="textPersonName" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" /> <EditText android:id="@+id/editText_note_content" android:layout_width="0dp" android:layout_height="0dp" android:layout_marginStart="16dp" android:layout_marginLeft="16dp" android:layout_marginTop="16dp" android:layout_marginEnd="16dp" android:layout_marginRight="16dp" android:layout_marginBottom="16dp" android:ems="10" android:inputType="textMultiLine" app:layout_constraintBottom_toTopOf="@+id/linearLayout3" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/editText_note_title" /> <LinearLayout android:id="@+id/linearLayout3" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginStart="16dp" android:layout_marginLeft="16dp" android:layout_marginEnd="16dp" android:layout_marginRight="16dp" android:layout_marginBottom="16dp" android:orientation="horizontal" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent"> <Button android:id="@+id/button_save" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:text="Save" /> <Button android:id="@+id/button_cancel" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:text="Cancel" /> </LinearLayout> </androidx.constraintlayout.widget.ConstraintLayout>
5- Java Code
Note.java
package org.o7planning.sqlitedemo.bean; import java.io.Serializable; public class Note implements Serializable { private int noteId; private String noteTitle; private String noteContent; public Note() { } public Note(String noteTitle, String noteContent) { this.noteTitle= noteTitle; this.noteContent= noteContent; } public Note(int noteId, String noteTitle, String noteContent) { this.noteId= noteId; this.noteTitle= noteTitle; this.noteContent= noteContent; } public int getNoteId() { return noteId; } public void setNoteId(int noteId) { this.noteId = noteId; } public String getNoteTitle() { return noteTitle; } public void setNoteTitle(String noteTitle) { this.noteTitle = noteTitle; } public String getNoteContent() { return noteContent; } public void setNoteContent(String noteContent) { this.noteContent = noteContent; } @Override public String toString() { return this.noteTitle; } }
MyDatabaseHelper.java
package org.o7planning.sqlitedemo; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.util.Log; import org.o7planning.sqlitedemo.bean.Note; import java.util.ArrayList; import java.util.List; public class MyDatabaseHelper extends SQLiteOpenHelper { private static final String TAG = "SQLite"; // Database Version private static final int DATABASE_VERSION = 1; // Database Name private static final String DATABASE_NAME = "Note_Manager"; // Table name: Note. private static final String TABLE_NOTE = "Note"; private static final String COLUMN_NOTE_ID ="Note_Id"; private static final String COLUMN_NOTE_TITLE ="Note_Title"; private static final String COLUMN_NOTE_CONTENT = "Note_Content"; public MyDatabaseHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); } // Create table @Override public void onCreate(SQLiteDatabase db) { Log.i(TAG, "MyDatabaseHelper.onCreate ... "); // Script. String script = "CREATE TABLE " + TABLE_NOTE + "(" + COLUMN_NOTE_ID + " INTEGER PRIMARY KEY," + COLUMN_NOTE_TITLE + " TEXT," + COLUMN_NOTE_CONTENT + " TEXT" + ")"; // Execute Script. db.execSQL(script); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { Log.i(TAG, "MyDatabaseHelper.onUpgrade ... "); // Drop older table if existed db.execSQL("DROP TABLE IF EXISTS " + TABLE_NOTE); // Create tables again onCreate(db); } // If Note table has no data // default, Insert 2 records. public void createDefaultNotesIfNeed() { int count = this.getNotesCount(); if(count ==0 ) { Note note1 = new Note("Firstly see Android ListView", "See Android ListView Example in o7planning.org"); Note note2 = new Note("Learning Android SQLite", "See Android SQLite Example in o7planning.org"); this.addNote(note1); this.addNote(note2); } } public void addNote(Note note) { Log.i(TAG, "MyDatabaseHelper.addNote ... " + note.getNoteTitle()); SQLiteDatabase db = this.getWritableDatabase(); ContentValues values = new ContentValues(); values.put(COLUMN_NOTE_TITLE, note.getNoteTitle()); values.put(COLUMN_NOTE_CONTENT, note.getNoteContent()); // Inserting Row db.insert(TABLE_NOTE, null, values); // Closing database connection db.close(); } public Note getNote(int id) { Log.i(TAG, "MyDatabaseHelper.getNote ... " + id); SQLiteDatabase db = this.getReadableDatabase(); Cursor cursor = db.query(TABLE_NOTE, new String[] { COLUMN_NOTE_ID, COLUMN_NOTE_TITLE, COLUMN_NOTE_CONTENT }, COLUMN_NOTE_ID + "=?", new String[] { String.valueOf(id) }, null, null, null, null); if (cursor != null) cursor.moveToFirst(); Note note = new Note(Integer.parseInt(cursor.getString(0)), cursor.getString(1), cursor.getString(2)); // return note return note; } public List<Note> getAllNotes() { Log.i(TAG, "MyDatabaseHelper.getAllNotes ... " ); List<Note> noteList = new ArrayList<Note>(); // Select All Query String selectQuery = "SELECT * FROM " + TABLE_NOTE; SQLiteDatabase db = this.getWritableDatabase(); Cursor cursor = db.rawQuery(selectQuery, null); // looping through all rows and adding to list if (cursor.moveToFirst()) { do { Note note = new Note(); note.setNoteId(Integer.parseInt(cursor.getString(0))); note.setNoteTitle(cursor.getString(1)); note.setNoteContent(cursor.getString(2)); // Adding note to list noteList.add(note); } while (cursor.moveToNext()); } // return note list return noteList; } public int getNotesCount() { Log.i(TAG, "MyDatabaseHelper.getNotesCount ... " ); String countQuery = "SELECT * FROM " + TABLE_NOTE; SQLiteDatabase db = this.getReadableDatabase(); Cursor cursor = db.rawQuery(countQuery, null); int count = cursor.getCount(); cursor.close(); // return count return count; } public int updateNote(Note note) { Log.i(TAG, "MyDatabaseHelper.updateNote ... " + note.getNoteTitle()); SQLiteDatabase db = this.getWritableDatabase(); ContentValues values = new ContentValues(); values.put(COLUMN_NOTE_TITLE, note.getNoteTitle()); values.put(COLUMN_NOTE_CONTENT, note.getNoteContent()); // updating row return db.update(TABLE_NOTE, values, COLUMN_NOTE_ID + " = ?", new String[]{String.valueOf(note.getNoteId())}); } public void deleteNote(Note note) { Log.i(TAG, "MyDatabaseHelper.updateNote ... " + note.getNoteTitle() ); SQLiteDatabase db = this.getWritableDatabase(); db.delete(TABLE_NOTE, COLUMN_NOTE_ID + " = ?", new String[] { String.valueOf(note.getNoteId()) }); db.close(); } }
MainActivity.java
package org.o7planning.sqlitedemo; import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.app.Activity; import android.app.AlertDialog; import android.content.DialogInterface; import android.content.Intent; import android.view.ContextMenu; import android.view.MenuItem; import android.view.View; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.ListView; import android.widget.Toast; import org.o7planning.sqlitedemo.bean.Note; import java.util.ArrayList; import java.util.List; public class MainActivity extends AppCompatActivity { private ListView listView; private static final int MENU_ITEM_VIEW = 111; private static final int MENU_ITEM_EDIT = 222; private static final int MENU_ITEM_CREATE = 333; private static final int MENU_ITEM_DELETE = 444; private static final int MY_REQUEST_CODE = 1000; private final List<Note> noteList = new ArrayList<Note>(); private ArrayAdapter<Note> listViewAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // Get ListView object from xml this.listView = (ListView) findViewById(R.id.listView); MyDatabaseHelper db = new MyDatabaseHelper(this); db.createDefaultNotesIfNeed(); List<Note> list= db.getAllNotes(); this.noteList.addAll(list); // Define a new Adapter // 1 - Context // 2 - Layout for the row // 3 - ID of the TextView to which the data is written // 4 - the List of data this.listViewAdapter = new ArrayAdapter<Note>(this, android.R.layout.simple_list_item_1, android.R.id.text1, this.noteList); // Assign adapter to ListView this.listView.setAdapter(this.listViewAdapter); // Register the ListView for Context menu registerForContextMenu(this.listView); } @Override public void onCreateContextMenu(ContextMenu menu, View view, ContextMenu.ContextMenuInfo menuInfo) { super.onCreateContextMenu(menu, view, menuInfo); menu.setHeaderTitle("Select The Action"); // groupId, itemId, order, title menu.add(0, MENU_ITEM_VIEW , 0, "View Note"); menu.add(0, MENU_ITEM_CREATE , 1, "Create Note"); menu.add(0, MENU_ITEM_EDIT , 2, "Edit Note"); menu.add(0, MENU_ITEM_DELETE, 4, "Delete Note"); } @Override public boolean onContextItemSelected(MenuItem item){ AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo(); final Note selectedNote = (Note) this.listView.getItemAtPosition(info.position); if(item.getItemId() == MENU_ITEM_VIEW){ Toast.makeText(getApplicationContext(),selectedNote.getNoteContent(),Toast.LENGTH_LONG).show(); } else if(item.getItemId() == MENU_ITEM_CREATE){ Intent intent = new Intent(this, AddEditNoteActivity.class); // Start AddEditNoteActivity, (with feedback). this.startActivityForResult(intent, MY_REQUEST_CODE); } else if(item.getItemId() == MENU_ITEM_EDIT ){ Intent intent = new Intent(this, AddEditNoteActivity.class); intent.putExtra("note", selectedNote); // Start AddEditNoteActivity, (with feedback). this.startActivityForResult(intent,MY_REQUEST_CODE); } else if(item.getItemId() == MENU_ITEM_DELETE){ // Ask before deleting. new AlertDialog.Builder(this) .setMessage(selectedNote.getNoteTitle()+". Are you sure you want to delete?") .setCancelable(false) .setPositiveButton("Yes", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int id) { deleteNote(selectedNote); } }) .setNegativeButton("No", null) .show(); } else { return false; } return true; } // Delete a record private void deleteNote(Note note) { MyDatabaseHelper db = new MyDatabaseHelper(this); db.deleteNote(note); this.noteList.remove(note); // Refresh ListView. this.listViewAdapter.notifyDataSetChanged(); } // When AddEditNoteActivity completed, it sends feedback. // (If you start it using startActivityForResult ()) @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); if (resultCode == Activity.RESULT_OK && requestCode == MY_REQUEST_CODE) { boolean needRefresh = data.getBooleanExtra("needRefresh", true); // Refresh ListView if (needRefresh) { this.noteList.clear(); MyDatabaseHelper db = new MyDatabaseHelper(this); List<Note> list = db.getAllNotes(); this.noteList.addAll(list); // Notify the data change (To refresh the ListView). this.listViewAdapter.notifyDataSetChanged(); } } } }
AddEditNoteActivity.java
package org.o7planning.sqlitedemo; import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.content.Intent; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; import android.app.Activity; import org.o7planning.sqlitedemo.bean.Note; public class AddEditNoteActivity extends AppCompatActivity { private static final int MODE_CREATE = 1; private static final int MODE_EDIT = 2; private EditText textTitle; private EditText textContent; private Button buttonSave; private Button buttonCancel; private Note note; private boolean needRefresh; private int mode; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_add_edit_note); this.textTitle = (EditText)this.findViewById(R.id.editText_note_title); this.textContent = (EditText)this.findViewById(R.id.editText_note_content); this.buttonSave = (Button)findViewById(R.id.button_save); this.buttonCancel = (Button)findViewById(R.id.button_cancel); this.buttonSave.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { buttonSaveClicked(); } }); this.buttonCancel.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { buttonCancelClicked(); } }); Intent intent = this.getIntent(); this.note = (Note) intent.getSerializableExtra("note"); if(note== null) { this.mode = MODE_CREATE; } else { this.mode = MODE_EDIT; this.textTitle.setText(note.getNoteTitle()); this.textContent.setText(note.getNoteContent()); } } // User Click on the Save button. public void buttonSaveClicked() { MyDatabaseHelper db = new MyDatabaseHelper(this); String title = this.textTitle.getText().toString(); String content = this.textContent.getText().toString(); if(title.equals("") || content.equals("")) { Toast.makeText(getApplicationContext(), "Please enter title & content", Toast.LENGTH_LONG).show(); return; } if(mode == MODE_CREATE ) { this.note= new Note(title,content); db.addNote(note); } else { this.note.setNoteTitle(title); this.note.setNoteContent(content); db.updateNote(note); } this.needRefresh = true; // Back to MainActivity. this.onBackPressed(); } // User Click on the Cancel button. public void buttonCancelClicked() { // Do nothing, back MainActivity. this.onBackPressed(); } // When completed this Activity, // Send feedback to the Activity called it. @Override public void finish() { // Create Intent Intent data = new Intent(); // Request MainActivity refresh its ListView (or not). data.putExtra("needRefresh", needRefresh); // Set Result this.setResult(Activity.RESULT_OK, data); super.finish(); } }
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How To Create A Database In Android Sqlite Tutorial
Source: https://o7planning.org/10433/android-sqlite-database
Posted by: inmansomper.blogspot.com
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