database sql

1SQL full form is a structured query language, and it allows you to interact through commands with the database. Here are some of the SQL Database functions:
2
3This allows users to retrieve information from the relational database.
4It enables the development of tables and databases.
5It allows data base and tables to be modified, added, removed, and changed.
6It gives protection, and allows permission to be set.
7Allows new ways for people to manage the info.

1SQL is a domain-specific language used in programming and designed for managing
2data held in a relational database management system, or for stream processing
3in a relational data stream management system.

1SQL is basically a programming language that lets people manipulate databases.

1package com.example.sairamkrishna.myapplication;
2
3import java.util.ArrayList;
4import java.util.HashMap;
5import java.util.Hashtable;
6import android.content.ContentValues;
7import android.content.Context;
8import android.database.Cursor;
9import android.database.DatabaseUtils;
10import android.database.sqlite.SQLiteOpenHelper;
11import android.database.sqlite.SQLiteDatabase;
12
13public class DBHelper extends SQLiteOpenHelper {
14
15   public static final String DATABASE_NAME = "MyDBName.db";
16   public static final String CONTACTS_TABLE_NAME = "contacts";
17   public static final String CONTACTS_COLUMN_ID = "id";
18   public static final String CONTACTS_COLUMN_NAME = "name";
19   public static final String CONTACTS_COLUMN_EMAIL = "email";
20   public static final String CONTACTS_COLUMN_STREET = "street";
21   public static final String CONTACTS_COLUMN_CITY = "place";
22   public static final String CONTACTS_COLUMN_PHONE = "phone";
23   private HashMap hp;
24
25   public DBHelper(Context context) {
26      super(context, DATABASE_NAME , null, 1);
27   }
28
29   @Override
30   public void onCreate(SQLiteDatabase db) {
31      // TODO Auto-generated method stub
32      db.execSQL(
33         "create table contacts " +
34         "(id integer primary key, name text,phone text,email text, street text,place text)"
35      );
36   }
37
38   @Override
39   public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
40      // TODO Auto-generated method stub
41      db.execSQL("DROP TABLE IF EXISTS contacts");
42      onCreate(db);
43   }
44
45   public boolean insertContact (String name, String phone, String email, String street,String place) {
46      SQLiteDatabase db = this.getWritableDatabase();
47      ContentValues contentValues = new ContentValues();
48      contentValues.put("name", name);
49      contentValues.put("phone", phone);
50      contentValues.put("email", email);	
51      contentValues.put("street", street);
52      contentValues.put("place", place);
53      db.insert("contacts", null, contentValues);
54      return true;
55   }
56   
57   public Cursor getData(int id) {
58      SQLiteDatabase db = this.getReadableDatabase();
59      Cursor res =  db.rawQuery( "select * from contacts where id="+id+"", null );
60      return res;
61   }
62   
63   public int numberOfRows(){
64      SQLiteDatabase db = this.getReadableDatabase();
65      int numRows = (int) DatabaseUtils.queryNumEntries(db, CONTACTS_TABLE_NAME);
66      return numRows;
67   }
68   
69   public boolean updateContact (Integer id, String name, String phone, String email, String street,String place) {
70      SQLiteDatabase db = this.getWritableDatabase();
71      ContentValues contentValues = new ContentValues();
72      contentValues.put("name", name);
73      contentValues.put("phone", phone);
74      contentValues.put("email", email);
75      contentValues.put("street", street);
76      contentValues.put("place", place);
77      db.update("contacts", contentValues, "id = ? ", new String[] { Integer.toString(id) } );
78      return true;
79   }
80
81   public Integer deleteContact (Integer id) {
82      SQLiteDatabase db = this.getWritableDatabase();
83      return db.delete("contacts", 
84      "id = ? ", 
85      new String[] { Integer.toString(id) });
86   }
87   
88   public ArrayList<String> getAllCotacts() {
89      ArrayList<String> array_list = new ArrayList<String>();
90      
91      //hp = new HashMap();
92      SQLiteDatabase db = this.getReadableDatabase();
93      Cursor res =  db.rawQuery( "select * from contacts", null );
94      res.moveToFirst();
95      
96      while(res.isAfterLast() == false){
97         array_list.add(res.getString(res.getColumnIndex(CONTACTS_COLUMN_NAME)));
98         res.moveToNext();
99      }
100      return array_list;
101   }
102}