Android SQLite數(shù)據(jù)庫增刪改查操作的案例分析
Person實體類
package com.ljq.domain;
public class Person {
private Integer id;
private String name;
private String phone;
public Person() {
super();
}
public Person(String name, String phone) {
super();
this.name = name;
this.phone = phone;
}
public Person(Integer id, String name, String phone) {
super();
this.id = id;
this.name = name;
this.phone = phone;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
}
DBOpenHelper數(shù)據(jù)庫關(guān)聯(lián)類
package com.ljq.db;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DBOpenHelper extends SQLiteOpenHelper {
// 類沒有實例化,是不能用作父類構(gòu)造器的參數(shù),必須聲明為靜態(tài)
private static final String DBNAME = "ljq.db";
private static final int VERSION = 1;
// 第三個參數(shù)CursorFactory指定在執(zhí)行查詢時獲得一個游標(biāo)實例的工廠類,
// 設(shè)置為null,代表使用系統(tǒng)默認(rèn)的工廠類
public DBOpenHelper(Context context) {
super(context, DBNAME, null, VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE PERSON (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME VARCHAR(20), PHONE VARCHAR(20))");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// 注:生產(chǎn)環(huán)境上不能做刪除操作
db.execSQL("DROP TABLE IF EXISTS PERSON");
onCreate(db);
}
}
PersonService業(yè)務(wù)類
package com.ljq.db;
import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.database.Cursor;
import com.ljq.domain.Person;
public class PersonService {
private DBOpenHelper dbOpenHelper = null;
/**
* 構(gòu)造函數(shù)
*
* 調(diào)用getWritableDatabase()或getReadableDatabase()方法后,會緩存SQLiteDatabase實例;
* 因為這里是手機(jī)應(yīng)用程序,一般只有一個用戶訪問數(shù)據(jù)庫,所以建議不關(guān)閉數(shù)據(jù)庫,保持連接狀態(tài)。
* getWritableDatabase(),getReadableDatabase的區(qū)別是當(dāng)數(shù)據(jù)庫寫滿時,調(diào)用前者會報錯,調(diào)用后者不會,
* 所以如果不是更新數(shù)據(jù)庫的話,最好調(diào)用后者來獲得數(shù)據(jù)庫連接。
*
* 對于熟悉SQL語句的程序員最好使用exeSQL(),rawQuery(),因為比較直觀明了
*
* @param context
*/
public PersonService(Context context){
dbOpenHelper = new DBOpenHelper(context);
}
public void save(Person person){
dbOpenHelper.getWritableDatabase().execSQL("insert into person(name, phone) values (?, ?)",
new Object[]{person.getName(), person.getPhone()});
}
public void update(Person person){
dbOpenHelper.getWritableDatabase().execSQL("update person set name=?, phone=? where id=?",
new Object[]{person.getName(), person.getPhone(), person.getId()});
}
public void delete(Integer... ids){
if(ids.length>0){
StringBuffer sb = new StringBuffer();
for(Integer id : ids){
sb.append("?").append(",");
}
sb.deleteCharAt(sb.length() - 1);
dbOpenHelper.getWritableDatabase().execSQL("delete from person where id in ("+sb+")", (Object[])ids);
}
}
public Person find(Integer id){
Cursor cursor = dbOpenHelper.getReadableDatabase().rawQuery("select id, name, phone from person where id=?",
new String[]{String.valueOf(id)});
if(cursor.moveToNext()){
int personid = cursor.getInt(0);
String name = cursor.getString(1);
String phone = cursor.getString(2);
return new Person(personid, name, phone);
}
return null;
}
public long getCount(){
Cursor cursor = dbOpenHelper.getReadableDatabase().query("person",
new String[]{"count(*)"}, null,null,null,null,null);
if(cursor.moveToNext()){
return cursor.getLong(0);
}
return 0;
}
/**
* 分頁
*
* @param startResult 偏移量,默認(rèn)從0開始
* @param maxResult 每頁顯示的條數(shù)
* @return
*/
public List<Person> getScrollData(int startResult, int maxResult){
List<Person> persons = new ArrayList<Person>();
//Cursor cursor = dbOpenHelper.getReadableDatabase().query("person", new String[]{"id, name, phone"},
// "name like ?", new String[]{"%ljq%"}, null, null, "id desc", "1,2");
Cursor cursor = dbOpenHelper.getReadableDatabase().rawQuery("select * from person limit ?,?",
new String[]{String.valueOf(startResult), String.valueOf(maxResult)});
while(cursor.moveToNext()) {
int personid = cursor.getInt(0);
String name = cursor.getString(1);
String phone = cursor.getString(2);
persons.add(new Person(personid, name, phone));
}
return persons;
}
}
PersonServiceTest測試類
package com.ljq.test;
import java.util.List;
import com.ljq.db.PersonService;
import com.ljq.domain.Person;
import android.test.AndroidTestCase;
import android.util.Log;
public class PersonServiceTest extends AndroidTestCase{
private final String TAG = "PersonServiceTest";
public void testSave() throws Exception{
PersonService personService = new PersonService(this.getContext());
personService.save(new Person("zhangsan1", "059188893343"));
personService.save(new Person("zhangsan2", "059188893343"));
personService.save(new Person("zhangsan3", "059188893343"));
personService.save(new Person("zhangsan4", "059188893343"));
personService.save(new Person("zhangsan5", "059188893343"));
}
public void testUpdate() throws Exception{
PersonService personService = new PersonService(this.getContext());
Person person = personService.find(1);
person.setName("linjiqin");
personService.update(person);
}
public void testFind() throws Exception{
PersonService personService = new PersonService(this.getContext());
Person person = personService.find(1);
Log.i(TAG, person.getName());
}
public void testList() throws Exception{
PersonService personService = new PersonService(this.getContext());
List<Person> persons = personService.getScrollData(0, 10);
for(Person person : persons){
Log.i(TAG, person.getId() + " : " + person.getName());
}
}
public void testCount() throws Exception{
PersonService personService = new PersonService(this.getContext());
Log.i(TAG, String.valueOf(personService.getCount()));
}
public void testDelete() throws Exception{
PersonService personService = new PersonService(this.getContext());
personService.delete(1);
}
public void testDeleteMore() throws Exception{
PersonService personService = new PersonService(this.getContext());
personService.delete(new Integer[]{2, 5, 6});
}
}
運(yùn)行結(jié)果
相關(guān)文章
Android XRecyclerView實現(xiàn)多條目加載
這篇文章主要為大家詳細(xì)介紹了Android XRecyclerView實現(xiàn)多條目加載效果,文中示例代碼介紹的非常詳細(xì),具有一定的參考價值,感興趣的小伙伴們可以參考一下2017-10-10Android webView如何輸出自定義網(wǎng)頁
這篇文章主要介紹了Android webView如何輸出自定義網(wǎng)頁,文中通過示例代碼介紹的非常詳細(xì),對大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價值,需要的朋友可以參考下2020-09-09Android中實現(xiàn)在矩形框中輸入文字顯示剩余字?jǐn)?shù)的功能
在矩形輸入框框中輸入文字顯示剩余字?jǐn)?shù)的功能在app開發(fā)中經(jīng)常會見到,今天小編就通過實例代碼給大家分享android實現(xiàn)輸入框提示剩余字?jǐn)?shù)功能,代碼簡單易懂,需要的朋友參考下吧2017-04-04Android利用LitePal操作數(shù)據(jù)庫存取圖片
這篇文章主要為大家詳細(xì)介紹了Android利用LitePal操作數(shù)據(jù)庫存取圖片的方法,具有一定的參考價值,感興趣的小伙伴們可以參考一下2017-08-08Android實現(xiàn)自定義ImageView的圓角矩形圖片效果
android顯示圓角矩形的圖片其原理就是首先獲取到圖片的Bitmap,然后進(jìn)行裁剪對應(yīng)的圓角矩形的bitmap,然后在onDraw()進(jìn)行繪制圓角矩形圖片輸出2018-05-05Android開發(fā)實現(xiàn)SubMenu選項菜單和子菜單示例
這篇文章主要介紹了Android開發(fā)實現(xiàn)SubMenu選項菜單和子菜單,結(jié)合實例形式分析了Android開發(fā)中SubMenu選項菜單和子菜單的功能、配置、布局等相關(guān)操作技巧,需要的朋友可以參考下2019-03-03Android WebView 不支持 H5 input type="file" 解決方法
這篇文章主要介紹了Android WebView 不支持 H5 input type="file" 解決方法,需要的朋友可以參考下2017-06-06