Android SQLite数据库增删改查

推荐一个查看SQLite数据库的工具

SQLite Developer 3.9.2下载地址：

http://www.sqlitedeveloper.com/

DBOpenHelper.java

[java]
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package cn.itcast.service;

import android.content.Context;

import android.database.sqlite.SQLiteDatabase;

import android.database.sqlite.SQLiteOpenHelper;

public class DBOpenHelper
extends SQLiteOpenHelper {
private static
final String DATABASENAME = "itcast.db";
//数据库名称
private static
final int DATABASEVERSION =
2;//数据库版本

public DBOpenHelper(Context context) {

super(context, DATABASENAME,
null, DATABASEVERSION);
}

@Override

public void onCreate(SQLiteDatabase db) {

db.execSQL("CREATE TABLE person (personid integer primary key autoincrement, name varchar(20), amount integer)");//执行有更改的sql语句

}

@Override
public void onUpgrade(SQLiteDatabase db,
int oldVersion, int newVersion) {

db.execSQL("DROP TABLE IF EXISTS person");

onCreate(db);
}

}

package cn.itcast.service;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DBOpenHelper extends SQLiteOpenHelper {
private static final String DATABASENAME = "itcast.db"; //数据库名称
private static final int DATABASEVERSION = 2;//数据库版本

public DBOpenHelper(Context context) {
super(context, DATABASENAME, null, DATABASEVERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE person (personid integer primary key autoincrement, name varchar(20), amount integer)");//执行有更改的sql语句
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS person");
onCreate(db);
}

}

PersonService.java

[java]
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package cn.itcast.service;

import java.util.ArrayList;

import java.util.List;

import android.content.Context;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

import cn.itcast.domain.Person;

public class PersonService {

private DBOpenHelper dbOpenHelper;

public PersonService(Context context) {

this.dbOpenHelper = new DBOpenHelper(context);

}

public void save(Person person){

//如果要对数据进行更改，就调用此方法得到用于操作数据库的实例,该方法以读和写方式打开数据库

SQLiteDatabase db = dbOpenHelper.getWritableDatabase();

db.execSQL("insert into person (name) values(?)",
new Object[]{person.getName()});

}

public void update(Person person){

SQLiteDatabase db = dbOpenHelper.getWritableDatabase();

db.execSQL("update person set name=? where personid=?",

new Object[]{person.getName(),person.getId()});

}

public void delete(Integer id){

SQLiteDatabase db = dbOpenHelper.getWritableDatabase();

db.execSQL("delete from person where personid=?",
new Object[]{id.toString()});
}

public Person find(Integer id){

//如果只对数据进行读取，建议使用此方法

SQLiteDatabase db = dbOpenHelper.getReadableDatabase();

Cursor cursor = db.rawQuery("select * from person where personid=?",
new String[]{id.toString()});
if(cursor.moveToFirst()){

int personid = cursor.getInt(cursor.getColumnIndex("personid"));

String name = cursor.getString(cursor.getColumnIndex("name"));

return
new Person(personid, name);
}
return null;

}

public List<Person> getScrollData(Integer offset, Integer maxResult){

List<Person> persons = new ArrayList<Person>();

SQLiteDatabase db = dbOpenHelper.getReadableDatabase();

Cursor cursor = db.rawQuery("select * from person limit ?,?",

new String[]{offset.toString(), maxResult.toString()});

while(cursor.moveToNext()){

int personid = cursor.getInt(cursor.getColumnIndex("personid"));

String name = cursor.getString(cursor.getColumnIndex("name"));

Person person = new Person(personid, name);

persons.add(person);
}
cursor.close();
return persons;
}

public long getCount() {

SQLiteDatabase db = dbOpenHelper.getReadableDatabase();

Cursor cursor = db.rawQuery("select count(*) from person",
null);
cursor.moveToFirst();
return cursor.getLong(0);

}
}

package cn.itcast.service;

import java.util.ArrayList;
import java.util.List;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

import cn.itcast.domain.Person;

public class PersonService {
private DBOpenHelper dbOpenHelper;

public PersonService(Context context) {
this.dbOpenHelper = new DBOpenHelper(context);
}

public void save(Person person){
//如果要对数据进行更改，就调用此方法得到用于操作数据库的实例,该方法以读和写方式打开数据库
SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
db.execSQL("insert into person (name) values(?)", new Object[]{person.getName()});
}

public void update(Person person){
SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
db.execSQL("update person set name=? where personid=?",
new Object[]{person.getName(),person.getId()});
}

public void delete(Integer id){
SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
db.execSQL("delete from person where personid=?", new Object[]{id.toString()});
}

public Person find(Integer id){
//如果只对数据进行读取，建议使用此方法
SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
Cursor cursor = db.rawQuery("select * from person where personid=?", new String[]{id.toString()});
if(cursor.moveToFirst()){
int personid = cursor.getInt(cursor.getColumnIndex("personid"));
String name = cursor.getString(cursor.getColumnIndex("name"));
return new Person(personid, name);
}
return null;
}

public List<Person> getScrollData(Integer offset, Integer maxResult){
List<Person> persons = new ArrayList<Person>();
SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
Cursor cursor = db.rawQuery("select * from person limit ?,?",
new String[]{offset.toString(), maxResult.toString()});
while(cursor.moveToNext()){
int personid = cursor.getInt(cursor.getColumnIndex("personid"));
String name = cursor.getString(cursor.getColumnIndex("name"));
Person person = new Person(personid, name);
persons.add(person);
}
cursor.close();
return persons;
}

public long getCount() {
SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
Cursor cursor = db.rawQuery("select count(*) from person", null);
cursor.moveToFirst();
return cursor.getLong(0);
}
}

测试类：PersonServiceTest.java

[java]
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package cn.itcast.db;

import java.util.List;

import cn.itcast.domain.Person;

import cn.itcast.service.DBOpenHelper;

import cn.itcast.service.PersonService;

import android.test.AndroidTestCase;

import android.util.Log;

public class PersonServiceTest
extends AndroidTestCase {
private static
final String TAG = "PersonServiceTest";

public void testCreateDB()
throws Throwable{
DBOpenHelper dbOpenHelper = new DBOpenHelper(this.getContext());

dbOpenHelper.getWritableDatabase();//第一次调用该方法就会创建数据库

}

public void testSave()
throws Throwable{
PersonService personService = new PersonService(this.getContext());

Person person = new Person();

person.setName("xiaoxiao");

personService.save(person);

person = new Person();

person.setName("zhangliming");

personService.save(person);

person = new Person();

person.setName("libaobao");

personService.save(person);

person = new Person();

person.setName("taobao");

personService.save(person);
}

public void testUpate()
throws Throwable{
PersonService personService =
new PersonService(this.getContext());

Person person = personService.find(1);

person.setName("lili");

personService.update(person);
}

public void testDelete()
throws Throwable{
PersonService personService = new PersonService(this.getContext());

personService.delete(1);

}

public void testFind()
throws Throwable{
PersonService personService =
new PersonService(this.getContext());

Person person = personService.find(1);

Log.i(TAG, person.toString());
}

public void testGetScrollData()
throws Throwable{
PersonService personService =
new PersonService(this.getContext());

List<Person> persons = personService.getScrollData(0,
3);
for(Person person : persons){

Log.i(TAG, person.toString());
}
}

public void testGetCount()
throws Throwable{
PersonService personService =
new PersonService(this.getContext());

Log.i(TAG, personService.getCount()+"");

}
}