十一、SQLite数据库增删改查操作案例

发布时间:2018-11-15  栏目:sqlite  评论:0 Comments

    public void testUpdate() throws Exception{
        PersonService personService = new
PersonService(this.getContext());
        Person person = personService.find(1);
        person.setName(“linjiqin”);
        personService.update(person);
    }

         

PersonService业务类

package com.ljq.db;

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

public class DBOpenHelper extends SQLiteOpenHelper {
    // 类没有实例化,是不能用作父类构造器的参数,必须声明为静态
    private static final String DBNAME = "ljq.db";
    private static final int VERSION = 1;

    // 第三个参数CursorFactory指定在执行查询时获得一个游标实例的工厂类,
    // 设置为null,代表使用系统默认的工厂类
    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:生产环境上不能做删除操作
        db.execSQL("DROP TABLE IF EXISTS PERSON"); 
        onCreate(db);
    }
}

    public void update(Person person){
        dbOpenHelper.getWritableDatabase().execSQL(“update person set
name=?, phone=? where id=?”,
                new Object[]{person.getName(), person.getPhone(),
person.getId()});
    }

               

public class PersonService {
    private DBOpenHelper dbOpenHelper = null;

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;
    }

}

    public String getPhone() {
        return phone;
    }

Person实体类

    /**
     * 构造函数
     *
     *
调用getWritableDatabase()或getReadableDatabase()方法后,会缓存SQLiteDatabase实例;
     *
因为此是手机应用程序,一般才发生一个用户访问数据库,所以建议不停歇数据库,保持连续状态。
     *
getWritableDatabase(),getReadableDatabase的别是当数据库写满时,调用前者会报错,调用后者不见面,
     * 所以如果未是创新数据库的话,最好调用后者来抱数据库连接。
     *
     *
对于熟悉SQL语句的程序员最好使用exeSQL(),rawQuery(),因为正如直观明了
     *
     * @param context
     */
    public PersonService(Context context){
        dbOpenHelper = new DBOpenHelper(context);
    }

            

    /**
     * 分页
     *
     * @param startResult 偏移量,默认从0开始
     * @param maxResult 每页显示的条数
     * @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;
    }

运行结果

import com.ljq.domain.Person;

PersonService业务类

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

PersonServiceTest测试类

    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;
    }

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});
    }
}

package com.ljq.db;

                  

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(“CREATE TABLE PERSON (ID INTEGER PRIMARY KEY
AUTOINCREMENT, NAME VARCHAR(20), PHONE VARCHAR(20))”);
    }

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;

    /**
     * 构造函数
     * 
     * 调用getWritableDatabase()或getReadableDatabase()方法后,会缓存SQLiteDatabase实例;
     * 因为这里是手机应用程序,一般只有一个用户访问数据库,所以建议不关闭数据库,保持连接状态。
     * getWritableDatabase(),getReadableDatabase的区别是当数据库写满时,调用前者会报错,调用后者不会,
     * 所以如果不是更新数据库的话,最好调用后者来获得数据库连接。
     * 
     * 对于熟悉SQL语句的程序员最好使用exeSQL(),rawQuery(),因为比较直观明了
     * 
     * @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;
    }

    /**
     * 分页
     * 
     * @param startResult 偏移量,默认从0开始
     * @param maxResult 每页显示的条数
     * @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;
    }



}

}

图片 1

public class PersonServiceTest extends AndroidTestCase{
    private final String TAG = “PersonServiceTest”;

           

    public Integer getId() {
        return id;
    }

DBOpenHelper数据库关联类

    public void testFind() throws Exception{
        PersonService personService = new
PersonService(this.getContext());
        Person person = personService.find(1);
        Log.i(TAG, person.getName());
    }

             

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int
newVersion) {
        // 注:生产条件达标不能够做去操作
        db.execSQL(“DROP TABLE IF EXISTS PERSON”);
        onCreate(db);
    }
}

                 

复制代码 代码如下:

            

运作结果

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

    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);
        }
    }

乃或许感兴趣的篇章:

  • Android
    SQLite数据库版本升级之管理落实
  • Android实现创建或者提升数据库时实施语句
  • Android
    SQLite数据库增删改查操作的运用详解
  • Android使用SQLite数据库的简单实例
  • 标准数据库Android:sqllite的简约用
  • Android中操作SQLite数据库快速入门教程
  • Android创建及动数据库SQLIte
  • Android
    数据库打包随APK发布的实例代码
  • Android操作SQLite数据库(增、删、改、查、分页等)及ListView显示数据的办法详解
  • Android开发中数据库升级还表上加新列的主意

复制代码 代码如下:

    public Person(String name, String phone) {
        super();
        this.name = name;
        this.phone = phone;
    }

import java.util.List;

图片 2

    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”));
    }

复制代码 代码如下:

    public String getName() {
        return name;
    }

Person实体类

package com.ljq.test;

public class Person {
    private Integer id;
    private String name;
    private String phone;

    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());
        }
    }

import android.test.AndroidTestCase;
import android.util.Log;

    public void setId(Integer id) {
        this.id = id;
    }

    public void save(Person person){
        dbOpenHelper.getWritableDatabase().execSQL(“insert into
person(name, phone) values (?, ?)”,
                new Object[]{person.getName(), person.getPhone()});
    }

   

    public Person() {
        super();
    }

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

    public void setName(String name) {
        this.name = name;
    }

    public Person(Integer id, String name, String phone) {
        super();
        this.id = id;
        this.name = name;
        this.phone = phone;
    }

    //
第三只参数CursorFactory指定在实践查询时获得一个游标实例的工厂类,
    // 设置为null,代表以系统默认的厂类
    public DBOpenHelper(Context context) {
        super(context, DBNAME, null, VERSION);
    }

DBOpenHelper数据库关联类

PersonServiceTest测试类

    public void testDelete() throws Exception{
        PersonService personService = new
PersonService(this.getContext());
        personService.delete(1);
    }

}

public class DBOpenHelper extends SQLiteOpenHelper {
    // 类没有实例化,是勿克就此作父类构造器的参数,必须声明也静态
    private static final String DBNAME = “ljq.db”;
    private static final int VERSION = 1;

    public void testCount() throws Exception{
        PersonService personService = new
PersonService(this.getContext());
        Log.i(TAG, String.valueOf(personService.getCount()));
    }

    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;
    }

    public void testDeleteMore() throws Exception{
        PersonService personService = new
PersonService(this.getContext());
        personService.delete(new Integer[]{2, 5, 6});
    }
}

package com.ljq.domain;

复制代码 代码如下:

package com.ljq.db;

import com.ljq.db.PersonService;
import com.ljq.domain.Person;

    public void setPhone(String phone) {
        this.phone = phone;
    }

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