Lab 6 Sqlite Part1

 Lab6 01 Layout

1.    Step 1: Launch Android Studio.  New Project

Fill the info as shown below :

Step 2: Select Phone and Tablet. Click Next ;
            Choose Empty Activity. Click Next
            Use default name as MainActivity. Click Finish

Step 3: Click on the activity_main.xml layout

Drag in a linearLayout (vertical) and click infer constraint

Create the followings:

1 linearLayout  (vertical)
1 TextView  tvTitle android:text="Telephone Directory"   1 EditText     etName android:hint="Enter name:" 1 EditText etTelNum android:hint="Enter Tel Number"
1 linearLayout  (horizontal)        android:layout_width="match_parent" android:layout_height="wrap_content"
2 Buttons  btnInsert and  btnViewData
1 TextView  tvStatus android:text="status"

Use proper naming convention (btn for Button, tv for TextView, et for EditText)

Test it out

 Lab6 01a Listener for Button

Step 4: Add a Sqlite Database in MainActivity.java

Place the codes in the correct sections  Here are the partial codes:

Declare the following class variables

//#1 Declare Class variables SQLiteDatabase db; Button btnInsert; EditText etName, etTel; TextView tvStatus;

Inside the onCreate method

//#2 Binding Java to XML tvStatus = (TextView) findViewById(R.id.tvStatus); btnInsert = (Button) findViewById(R.id.btnInsert); etName = (EditText) findViewById(R.id.etName); etTel = (EditText) findViewById(R.id.etTelNum);

After binding, add the listener for the 2 buttons.

Inside the onCreate method

//#3  ClickListener for btnInsert btnInsert.setOnClickListener(new View.OnClickListener() {     public void onClick(View arg0) { Toast.makeText(getApplicationContext(),"Inserted",Toast.LENGTH_LONG).show();     } }); //========btnInsert=========

Repeat the above for the listener for btnViewData (remember to do binding else you will encounter NullPointer exception)

Test it out

Lab6 02Insert

Step 1: Add a new Java Class called SqlLiteHelper

Step 2: //Create a executeSQL method Within the SqlLiteHelper class

public class SqlLiteHelper { //Create a method executeSQL for Insert, Delete , Update public String executeSQL(SQLiteDatabase db,String sql) { try { db.beginTransaction(); db.execSQL(sql); db.setTransactionSuccessful(); db.endTransaction(); } catch (Exception e) { System.out.println(e.toString()); return ("Error updating DB"); } return ("DB updated"); } }

Step 3: Edit  MainActivity.java

Declare the sqlh as class variable

SqlLiteHelper sqlh = new SqlLiteHelper(); //this create an object from SqlLiteHelper class

Add the following codes before //#2 Binding Java to XML

Inside the onCreate method

//#1 Create Database file name TelDirectory.db and Table name TelDirList db = openOrCreateDatabase("TelDirectory.db", MODE_PRIVATE, null); String sqlStatement = "create table if not exists TelDirList (recId integer PRIMARY KEY autoincrement, Name text, Tel text)"; sqlh.executeSQL(db, sqlStatement);

Inside the onClick method of btnInsert, add the following codes:

tvStatus.setText(""); //clear the text on tvStatus String name = etName.getText().toString(); //get text from EditText etName String tel = etTel.getText().toString();//get text from EditText etTel String sqlStatement = "insert into TelDirList (Name ,Tel) values( '" + name + "','" + tel + "')"; String result = sqlh.executeSQL(db, sqlStatement); //execute the Insert SQL command tvStatus.setText(result); //show the status by using setText on tvStatus

Test it out