Android SQLite CRUD – RecyclerView – Serverside Search/Filter
This tutorial helps us explore Android SQLite database searching or filtering data.
We are covering how to search/filter data against our SQLite database.Take note we are filtering at the SQlite side,not in java but in SQL,at the server side if you like.Our widget today is RecyclerView.We of course start from scratch,inserting,then selecting while applying a search.
First we have to save data and retrieve data from that database.
We render the data in our RecyclerView.
We will be searching/filtering data at the sqlite server level as opposed to fetching all data and filtering via Java.
This is what we do short:
- INSERT data to our SQlite database.
- SELECT that particular data,while applying a dynamic filter.
- Our search term is dynamically entered by the user via a searchview.
Let’s go.
1. Create Basic Activity Project
- First create a basic project in android studio. You can see how to do so here.
2. Add Dependencies
Lets add support library dependencies in our app level build.gradle:
dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) testCompile 'junit:junit:4.12' compile 'com.android.support:appcompat-v7:23.3.0' compile 'com.android.support:design:23.3.0' compile 'com.android.support:cardview-v7:23.3.0' }
3. Create User Interface
User interfaces are typically created in android using XML layouts as opposed by direct java coding.
Here are our layouts for this project:
(a). activity_main.xml
- This layout gets inflated to MainActivity user interface.
- It includes the content_main.xml.
<?xml version="1.0" encoding="utf-8"?> <android.support.design.widget.CoordinatorLayout android_layout_width="match_parent" android_layout_height="match_parent" android_fitsSystemWindows="true" tools_context="com.tutorials.hp.sqliteserversidefilter.MainActivity"> <android.support.design.widget.AppBarLayout android_layout_width="match_parent" android_layout_height="wrap_content" android_theme="@style/AppTheme.AppBarOverlay"> <android.support.v7.widget.Toolbar android_id="@+id/toolbar" android_layout_width="match_parent" android_layout_height="?attr/actionBarSize" android_background="?attr/colorPrimary" app_popupTheme="@style/AppTheme.PopupOverlay" /> </android.support.design.widget.AppBarLayout> <include layout="@layout/content_main" /> <android.support.design.widget.FloatingActionButton android_id="@+id/fab" android_layout_width="wrap_content" android_layout_height="wrap_content" android_layout_gravity="bottom|end" android_layout_margin="@dimen/fab_margin" android_src="@android:drawable/ic_dialog_email" /> </android.support.design.widget.CoordinatorLayout>
(b). content_main.xml
This layout gets included in your activity_main.xml.
You define your UI widgets right here.
In this case we will have a SearchView right on top of a RecyclerView.
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout android_layout_width="match_parent" android_layout_height="match_parent" android_paddingBottom="@dimen/activity_vertical_margin" android_paddingLeft="@dimen/activity_horizontal_margin" android_paddingRight="@dimen/activity_horizontal_margin" android_paddingTop="@dimen/activity_vertical_margin" app_layout_behavior="@string/appbar_scrolling_view_behavior" tools_context="com.tutorials.hp.sqliteserversidefilter.MainActivity" tools_showIn="@layout/activity_main"> <android.support.v7.widget.SearchView android_id="@+id/sv" android_layout_width="match_parent" android_layout_height="wrap_content" android_queryHint="Search.." ></android.support.v7.widget.SearchView> <android.support.v7.widget.RecyclerView android_id="@+id/rv" android_layout_below="@+id/sv" android_layout_width="match_parent" android_layout_height="wrap_content" ></android.support.v7.widget.RecyclerView> </RelativeLayout>
(c). dialog_layout.xml
This is the input dialog layout.
We will need to insert to and retrieve data from SQlite database so we will use this dialog as our input form. At the root we have a CardView. Then a LinearLayout with vertical orientation. Inside the LinearLayout we have TextInputLayout, which wraps our EditText.
<?xml version="1.0" encoding="utf-8"?> <android.support.v7.widget.CardView android_orientation="horizontal" android_layout_width="500dp" android_layout_margin="1dp" card_view_cardCornerRadius="10dp" card_view_cardElevation="5dp" android_layout_height="match_parent"> <LinearLayout android_layout_width="match_parent" android_orientation="vertical" android_layout_height="match_parent"> <android.support.design.widget.TextInputLayout android_id="@+id/nameLayout" android_layout_width="match_parent" android_layout_height="wrap_content"> <EditText android_id="@+id/nameEditTxt" android_layout_width="match_parent" android_layout_height="wrap_content" android_singleLine="true" android_hint= "Name" /> </android.support.design.widget.TextInputLayout> <Button android_id="@+id/saveBtn" android_layout_width="fill_parent" android_layout_height="wrap_content" android_text="Save" android_clickable="true" android_background="@color/colorAccent" android_layout_marginTop="40dp" android_textColor="@android:color/white"/> <Button android_id="@+id/retrieveBtn" android_layout_width="fill_parent" android_layout_height="wrap_content" android_text="Retrieve" android_clickable="true" android_background="@color/colorAccent" android_layout_marginTop="40dp" android_textColor="@android:color/white"/> </LinearLayout> </android.support.v7.widget.CardView>
(d). model.xml
This will define the template for each RecyclerView Viewitem. This layout will get inflated in our recycleview adapter class.
At the root we have a CardView.
<?xml version="1.0" encoding="utf-8"?> <android.support.v7.widget.CardView android_orientation="horizontal" android_layout_width="match_parent" android_layout_margin="5dp" card_view_cardCornerRadius="10dp" card_view_cardElevation="5dp" android_layout_height="wrap_content"> <RelativeLayout android_layout_width="match_parent" android_layout_height="match_parent"> <TextView android_layout_width="wrap_content" android_layout_height="wrap_content" android_textAppearance="?android:attr/textAppearanceLarge" android_text="Name" android_id="@+id/nameTxt" android_padding="10dp" android_layout_alignParentTop="true" /> </RelativeLayout> </android.support.v7.widget.CardView>
4. Java Classes
Here are our Java classes.
Our POJO
(a) Planet.java
Our data object.
Represents a single planet with several properties.
We will be saving planets in our SQLite database.
package com.tutorials.hp.sqliteserversidefilter.mDataObject; public class Planet { String name; int id; public Planet() { } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getId() { return id; } public void setId(int id) { this.id = id; } }
Our SQLite Classes
(a) Constants.java
First here’s our Constants class that’s going to hold all our SQlite database constants.
This class contains our SQLite database constants. These include: databse table name, database name, database version, column names, SQLite table creation and deletion statements.
package com.tutorials.hp.sqliteserversidefilter.mDataBase; public class Constants { //columns static final String ROW_ID="id"; static final String NAME="name"; //DB static final String DB_NAME="gg_DB"; static final String TB_NAME="gg_TB"; static final int DB_VERSION=1; //CREATE STMT static final String CREATE_TB="CREATE TABLE gg_TB(id INTEGER PRIMARY KEY AUTOINCREMENT," + "name TEXT NOT NULL);"; //DROP TB STMT static final String DROP_TB="DRP TABLE IF EXISTS "+TB_NAME; }
(b) DBHelper.java
This is our SQLiteHelper class.
We call it DBHelper and it is the class that shall be responsible for upgrading and creating our database table.
It Allows us to create table and upgrade it.
package com.tutorials.hp.sqliteserversidefilter.mDataBase; import android.content.Context; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; public class DBHelper extends SQLiteOpenHelper { public DBHelper(Context context) { super(context, Constants.DB_NAME, null, Constants.DB_VERSION); } @Override public void onCreate(SQLiteDatabase db) { try { db.execSQL(Constants.CREATE_TB); }catch (SQLException e) { e.printStackTrace(); } } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { db.execSQL(Constants.DROP_TB); onCreate(db); } }
(c) DBAdapter.java
Our database adapter class.
Basically responsible for performing CRUD activities like inserting and selecting to and from SQLite database.
We also open and close the SQLite database.
We also search here as part our data retrieval from sqlite database using a searchTerm passed to us.
Our DBAdapter class below is responsible for performing our CRUD operations including searching our database.We said we do the search at the server side or database level instead of via Java code :
package com.tutorials.hp.sqliteserversidefilter.mDataBase; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; public class DBAdapter { Context c; SQLiteDatabase db; DBHelper helper; public DBAdapter(Context c) { this.c = c; helper=new DBHelper(c); } //OPEN DB public void openDB() { try { db=helper.getWritableDatabase(); }catch (SQLException e) { e.printStackTrace(); } } //CLOSE public void closeDB() { try { helper.close(); }catch (SQLException e) { e.printStackTrace(); } } //SAVE OR INSERT public boolean add(String name) { try { ContentValues cv=new ContentValues(); cv.put(Constants.NAME, name); db.insert(Constants.TB_NAME, Constants.ROW_ID, cv); return true; }catch (SQLException e) { e.printStackTrace(); } return false; } //RETRIEVE OR FILTERING public Cursor retrieve(String searchTerm) { String[] columns={Constants.ROW_ID,Constants.NAME}; Cursor c=null; if(searchTerm != null && searchTerm.length()>0) { String sql="SELECT * FROM "+Constants.TB_NAME+" WHERE "+Constants.NAME+" LIKE '%"+searchTerm+"%'"; c=db.rawQuery(sql,null); return c; } c=db.query(Constants.TB_NAME,columns,null,null,null,null,null); return c; } }
Our RecyclerView Classes
(a) MyHolder.java
Our RecyclerView.ViewHolder class.
Holds a simple TextView.
package com.tutorials.hp.sqliteserversidefilter.mRecycler; import android.support.v7.widget.RecyclerView; import android.view.View; import android.widget.TextView; import com.tutorials.hp.sqliteserversidefilter.R; public class MyHolder extends RecyclerView.ViewHolder { TextView nameTxt; public MyHolder(View itemView) { super(itemView); this.nameTxt= (TextView) itemView.findViewById(R.id.nameTxt); } }
RecyclerView SQLite Database Data
(b) MyAdapter.java
Our RecyclerView.Adapter class.
Will inflate model.xml into a RecyclerView view item.
Will then bind data to those viewitems.
Below now is our RecyclerView adapter.It shall be bind our filtered data to the RecyclerView.
package com.tutorials.hp.sqliteserversidefilter.mRecycler; import android.content.Context; import android.support.v7.widget.RecyclerView; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import com.tutorials.hp.sqliteserversidefilter.R; import com.tutorials.hp.sqliteserversidefilter.mDataObject.Planet; import java.util.ArrayList; public class MyAdapter extends RecyclerView.Adapter<MyHolder> { Context c; ArrayList<Planet> planets; public MyAdapter(Context c, ArrayList<Planet> planets) { this.c = c; this.planets = planets; } @Override public MyHolder onCreateViewHolder(ViewGroup parent, int viewType) { View v= LayoutInflater.from(parent.getContext()).inflate(R.layout.model,parent,false); MyHolder holder=new MyHolder(v); return holder; } @Override public void onBindViewHolder(MyHolder holder, int position) { holder.nameTxt.setText(planets.get(position).getName()); } @Override public int getItemCount() { return planets.size(); } }
Our Activity Class
(a) MainActivity.java
Our launcher and only activity.
Provides us with the UI for our application.
Shows a RecyclerView and searchview. Listens to searchview change events to filter.
Also defines us an input dialog for data entry.
package com.tutorials.hp.sqliteserversidefilter; import android.app.Dialog; import android.database.Cursor; import android.os.Bundle; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.Snackbar; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.support.v7.widget.SearchView; import android.support.v7.widget.Toolbar; import android.view.View; import android.view.Menu; import android.view.MenuItem; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; import com.tutorials.hp.sqliteserversidefilter.mDataBase.DBAdapter; import com.tutorials.hp.sqliteserversidefilter.mDataObject.Planet; import com.tutorials.hp.sqliteserversidefilter.mRecycler.MyAdapter; import java.util.ArrayList; public class MainActivity extends AppCompatActivity { RecyclerView rv; SearchView sv; EditText nameTxt; Button saveBtn,retrieveBtn; ArrayList<Planet> planets=new ArrayList<>(); MyAdapter adapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); rv= (RecyclerView) findViewById(R.id.rv); rv.setLayoutManager(new LinearLayoutManager(this)); sv= (SearchView) findViewById(R.id.sv); adapter=new MyAdapter(this,planets); fab.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { displayDialog(); } }); sv.setOnQueryTextListener(new SearchView.OnQueryTextListener() { @Override public boolean onQueryTextSubmit(String query) { return false; } @Override public boolean onQueryTextChange(String query) { getPlanets(query); return false; } }); } private void displayDialog() { Dialog d=new Dialog(this); d.setTitle("SQLite Database"); d.setContentView(R.layout.dialog_layout); nameTxt= (EditText) d.findViewById(R.id.nameEditTxt); saveBtn= (Button) d.findViewById(R.id.saveBtn); retrieveBtn= (Button) d.findViewById(R.id.retrieveBtn); saveBtn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { save(nameTxt.getText().toString()); } }); retrieveBtn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { getPlanets(null); } }); //SHOW DIALOG d.show(); } private void save(String name) { DBAdapter db=new DBAdapter(this); db.openDB(); if(db.add(name)) { nameTxt.setText(""); }else { Toast.makeText(this,"Unable to Save",Toast.LENGTH_SHORT).show(); } db.closeDB(); getPlanets(null); } private void getPlanets(String searchTerm) { planets.clear(); DBAdapter db=new DBAdapter(this); db.openDB(); Planet p=null; Cursor c=db.retrieve(searchTerm); while (c.moveToNext()) { int id=c.getInt(0); String name=c.getString(1); p=new Planet(); p.setId(id); p.setName(name); planets.add(p); } db.closeDB(); rv.setAdapter(adapter); } }
Download
Download code below.
If you prefer more explanations or want to see the demo then the video tutorial is here.
No. | Location | Link |
---|---|---|
1. | GitHub | Direct Download) |
2. | GitHub | Browse |
3. | YouTube | Video Tutorial |
4. | YouTube | Our YouTube Channel |