Android SQLite DB Package

Source: Internet
Author: User
Tags sqlite db

Dbopenhelper:

Package com.example.db_demo01. DB;

import Android.content.Context;

import android.database.sqlite.SQLiteDatabase;

import Android.database.sqlite.SQLiteOpenHelper;

Public class Dbopenhelper extends sqliteopenhelper {

Private Static    String Name = "Mydb.db"; Database name

Private Static int            version = 1; Version number

Public Dbopenhelper (Context context) {

Super (Context, name, null, version);

}

@Override

Public void onCreate (sqlitedatabase db) {

String sql = "CREATE table person (ID integer primary key autoincrement, name varchar (+), address varchar (64))";

Db.execsql (SQL); Create a table

}

@Override

Public void Onupgrade (sqlitedatabase arg0, int arg1, int arg2) {

Update the version number at the same time when you update the table structure

}

}

Closure of the DB operation:

Package com.example.db_demo01. DB;

import java.util.ArrayList;

import Java.util.HashMap;

import java.util.List;

import Java.util.Map;

import Android.content.Context;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

Public class DB {

Private Dbopenhelper helper = null;

Public DB (Context context) {

Helper = New dbopenhelper (context);

}

Public Boolean Execsql (String sql) {

boolean flag = false;

Sqlitedatabase database = null;

Try {

Database = Helper.getwritabledatabase ();

Database.execsql (SQL);

Flag = true;

} catch (Exception e) {

E.printstacktrace ();

}finally{

if (Database! = null) {

Database.close ();

}

}

return flag;

}

Insert

Public Boolean Insert (String sql) {

return Execsql (SQL);

}

Delete

Public Boolean Delete (String sql) {

return Execsql (SQL);

}

Update

Public Boolean Update (String sql) {

return Execsql (SQL);

}

Inquire

Public List<map<string, string>> Query (String sql) {

Sqlitedatabase database = null;

list<map<string, string>> list = new arraylist<map<string, string>> ();

Try {

Database = Helper.getwritabledatabase ();

cursor cursor = database.rawquery (SQL, null);

int colums = Cursor.getcolumncount ();

while (Cursor.movetonext ()) {

map<string, string> map = new hashmap<string, string> ();

for (int i=0; i<colums; i++) {

String cols_name = Cursor.getcolumnname (i);

String Cols_value = cursor.getstring (Cursor.getcolumnindex (cols_name));

if (Cols_value = = null) {

Cols_value = "";

}

Map.put (Cols_name, Cols_value);

}

List.add (map);

}

} catch (Exception e) {

E.printstacktrace ();

}finally{

if (Database! = null) {

Database.close ();

}

}

return list;

}

}

Unit Test class:

Package com.example.db_demo01.test;

import java.util.ArrayList;

import java.util.List;

import Java.util.Map;

import android.test.AndroidTestCase;

Import com.example.db_demo01. Db. DB;

Import com.example.db_demo01. Db. Dbopenhelper;

Public class MyTest extends androidtestcase {

Public MyTest () {}

Public void Createdb () {

Dbopenhelper helper = new dbopenhelper (GetContext ());

Helper.getwritabledatabase ();

}

Public void Insert () {

DB db = new db (GetContext ());

String sql = "INSERT into person (name, address) VALUES (' Deng ', ' zhbit ')";

Db. Insert (SQL);

}

Public void Delete () {

DB db = new db (GetContext ());

String sql = "Delete from the person where name = ' Deng '";

System. out. println (db. Delete (SQL));

}

Public void Update () {

DB db = new db (GetContext ());

String sql = "Update person set name = ' Deng 2 ' where name = ' Deng '";

System. out. println (db. Delete (SQL));

}

Public void query () {

DB db = new db (getcontext());

String sql = "SELECT * from person";

list<map<string, string>> list = new arraylist<map<string, string>> ();

List = db. Query (SQL);

System. out. println (List.tostring ());

}

}

Android SQLite DB Package

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