Go语言视频零基础入门到精通

jjweji

sqlite属于一种嵌入式的数据库，并不像其他数据库要安装服务器端，只要安装android模拟器就可以对sqlite操作了。
首先写一个数据库的工具类 import android.content.Context;

import android.database.sqlite.SQLiteDatabase;

import android.database.sqlite.SQLiteOpenHelper;



public class DataBaseHepler extends SQLiteOpenHelper {



private static final String NAME = "sharp.db";



private static final int version = 1;



public DataBaseHepler(Context context) {

super(context, NAME, null, version);

}



@Override

public void onCreate(SQLiteDatabase db) {

db.execSQL("create table person(personid integer primary key autoincrement,name varchar(20),age integer)");

}



@Override

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



}



}
复制代码只需要在里面添加表就可以了
然后添加一个对象 public class Person {

private Integer id;

private String name;

private Integer age;



public Person(Integer id, String name, Integer age) {

super();

this.id = id;

this.name = name;

this.age = age;

}



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 Integer getAge() {

return age;

}



public void setAge(Integer age) {

this.age = age;

}



public Person(String name, Integer age) {

super();

this.name = name;

this.age = age;

}



public Person() {

super();

}  



public String toString(){

return "id = " + id + " name = " + name + " age = " + age;

}

}
复制代码之后写一个service类，里面包含数据库的一些基本的操作 import java.util.ArrayList;

import java.util.List;



import com.sharpandroid.domain.Person;



import android.content.Context;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;



public class PersonService {

private Context context;



private DataBaseHepler dataBaseHepler;



public PersonService(Context context) {

this.context = context;

dataBaseHepler = new DataBaseHepler(context);

}



public void save(Person person){

SQLiteDatabase database = dataBaseHepler.getWritableDatabase();

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

}



public void update(Person person){

SQLiteDatabase database = dataBaseHepler.getWritableDatabase();

database.execSQL("update person set name=?,age=? where personid=?",new Object[]{person.getName(),person.getAge(),person.getId()});

}



public Person find(Integer id){

SQLiteDatabase database = dataBaseHepler.getWritableDatabase();

Cursor cursor = database.rawQuery("select personid,name,age from person where personid=?", new String[]{String.valueOf(id)});

if(cursor.moveToNext()){

Person person = new Person();

person.setId(cursor.getInt(cursor.getColumnIndex("personid")));

person.setName(cursor.getString(1));

person.setAge(cursor.getInt(2));

return person;

}

cursor.close();

return null;

}



public void delete(Integer id){

SQLiteDatabase database = dataBaseHepler.getWritableDatabase();

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

}

public long getCount(){

SQLiteDatabase database = dataBaseHepler.getWritableDatabase();

Cursor cursor = database.rawQuery("select count(*) from person", null);

cursor.moveToFirst();

long count = cursor.getLong(0);

cursor.close();

return count;

}

}
复制代码在AndroidManifest.xml添加测试类 <?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

      package="com.android.activity"

      android:versionCode="1"

      android:versionName="1.0">





    <application android:icon="@drawable/icon" android:label="@string/app_name">

        <uses-library android:name="android.test.runner"/>

        <activity android:name=".PersonActivity"

                  android:label="@string/app_name">

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

    </application>

    <instrumentation android:name="android.test.InstrumentationTestRunner" android:targetPackage="com.sharpandroid.activity" android:label="Test for My App"/>

</manifest>
复制代码之后写一个测试单元就可以进行测试了 public class PersonServiceTest extends AndroidTestCase {

public void testSave() throws Throwable{

PersonService personService = new PersonService(this.getContext());

Person person = new Person("Tom",21);

personService.save(person);

}

}
复制代码要想看执行之后生成的数据库可以用File Explorer视图就可以看到生成之后的数据库文件，可以把生成之后的数据库导出来导入到sqlite可视化工具，就可以查看里面的数据，也可以用adb命令查看表中的数据