Android Small Note database

Create a table

CREATE TABLE person (_id integer PRIMARY key autoincrement,name varchar (+), age integer)

Inserting data

INSERT into person values (1, "Bojie", 18)

INSERT into person values (2, "Pange", 18)

Delete data

Delete from person where name= "Pange"

Querying data

Select name from the person where _id=2

modifying data

Update person set name= "Pange+tanji" where name= "Pange"

Sqlite

public class Mysqlitehelper extends Sqliteopenhelper {

/**

* Version 1

* Factory data lookup cursors default null>>> cursor

* Name Database name

* @param context

*/

Public Mysqlitehelper (context context) {

Super (context, "my.db", NULL, 1);

//TODO auto-generated constructor stub

}

@Override

public void onCreate (Sqlitedatabase db) {

db.execsql ("CREATE TABLE Person" (_id integer PRIMARY key autoincrement,name varchar (+), age integer) ");

}

DAO layer

public class Personservice {

Private Mysqlitehelper Helper;

Public Personservice (Context context) {

Helper = new Mysqlitehelper (context);

}

/**

* Insert Data

* @param p

*/

public void Insert (person p) {

Sqlitedatabase db = Helper.getwritabledatabase ();

Db.execsql ("INSERT INTO person values" ("+p.getname () +", "+p.getage () +") ");

if (Db.isopen ()) {

Db.execsql ("INSERT into person (name,age) VALUES (?,?)", New Object[]{p.getname (), P.getage ()});

}

Db.close ();

}

/**

* Delete Data

* @param name

*/

public void del (String name) {

Sqlitedatabase db = Helper.getwritabledatabase ();

if (Db.isopen ()) {

Db.execsql ("Delete from person where name=?", New String[]{name});

}

Db.close ();

}

/**

* Modify Data

* @param oldname

* @param newName

*/

public void Update (String oldname,string newName) {

Sqlitedatabase db = Helper.getwritabledatabase ();

if (Db.isopen ()) {

Db.execsql ("Update person set name=?") Where Name=? ", New String[]{newname,oldname});

}

Db.close ();

}

/**

* Query all data

* @return

*/

Public list<person> GetAll () {

List<person> lists=new arraylist<person> ();

Sqlitedatabase db = Helper.getreadabledatabase ();

if (Db.isopen ()) {

cursor cursor = db.rawquery ("Select name, age from person", NULL);

if (Cursor!=null&&cursor.getcount () >0) {

while (Cursor.movetonext ()) {

String name = cursor.getstring (0);

int age = Cursor.getint (1);

Person Person=new person (name, age);

Lists.add (person);

}

}

Cursor.close ();

return lists;

}

Db.close ();

return null;

}

/**

* Query the corresponding data

* @param ID

* @return

*/

Public person Getpersonbyid (int id) {

Sqlitedatabase db = Helper.getreadabledatabase ();

Person Person=new person ();

if (Db.isopen ()) {

cursor cursor = db.rawquery ("Select Name,age from person where _id=?", new String[]{string.valueof (ID)});

if (Cursor!=null&&cursor.getcount () >0) {

if (Cursor.movetolast ()) {

String name = cursor.getstring (0);

Person.setname (name);

int age = Cursor.getint (1);

Person.setage (age);

}

}

Cursor.close ();

return person;

}

Db.close ();

return null;

}

This article is from the "Android Small Notes" blog, please be sure to keep this source http://dreamwing.blog.51cto.com/9872128/1612138

Android Small Note database