03创建数据库和表以及测试数据库的操作(单元测试框架)

整体项目的框架如下:



省市县需要三张表:省,市,县:

建表的语言为:



注意有空格。

先在model包下新建省市县的实体类:

省:

package com.dy.ustc.weatherpro.model;

public class Province {

	private int id;

	private String provinceName;

	private String provinceCode;

	public int getId() {
		return id;
	}

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

	public String getProvinceName() {
		return provinceName;
	}

	public void setProvinceName(String provinceName) {
		this.provinceName = provinceName;
	}

	public String getProvinceCode() {
		return provinceCode;
	}

	public void setProvinceCode(String provinceCode) {
		this.provinceCode = provinceCode;
	}

}
市:
package com.dy.ustc.weatherpro.model;

public class City {

	private int id;

	private String cityName;

	private String cityCode;

	private int provinceId;

	public int getId() {
		return id;
	}

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

	public String getCityName() {
		return cityName;
	}

	public void setCityName(String cityName) {
		this.cityName = cityName;
	}

	public String getCityCode() {
		return cityCode;
	}

	public void setCityCode(String cityCode) {
		this.cityCode = cityCode;
	}

	public int getProvinceId() {
		return provinceId;
	}

	public void setProvinceId(int provinceId) {
		this.provinceId = provinceId;
	}

}

注意City表需要关联Province表,provinceId就是City表关联Province表的外键。

县:

package com.dy.ustc.weatherpro.model;

public class County {

	private int id;

	private String countyName;

	private String countyCode;

	private int cityId;

	public int getId() {
		return id;
	}

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

	public String getCountyName() {
		return countyName;
	}

	public void setCountyName(String countyName) {
		this.countyName = countyName;
	}

	public String getCountyCode() {
		return countyCode;
	}

	public void setCountyCode(String countyCode) {
		this.countyCode = countyCode;
	}

	public int getCityId() {
		return cityId;
	}

	public void setCityId(int cityId) {
		this.cityId = cityId;
	}
	
}

其中city_id是County表关联City表的外键。

这时候我们可以执行创建表的语句了,在db包下,新建:CoolWeatherOpenHelper继承自:SQLiteOpenHelper,创建好了之后,需要指定构造器和onCreate()方法以及onUpgrade()方法,升级数据库的方法这里不用管它。

先看构造器的代码:

public CoolWeatherOpenHelper(Context context, String name, CursorFactory factory,
			int version) {
		super(context, name, factory, version);
	}

context为上下文,name为数据库的名字,factory为游标工厂,version为数据库的版本。

	@Override
	public void onCreate(SQLiteDatabase db) {
		db.execSQL(CREATE_PROVINCE);  // 创建Province表
		db.execSQL(CREATE_CITY);  // 创建City表
		db.execSQL(CREATE_COUNTY);  // 创建County表
	}

完整的代码:

package com.dy.ustc.weatherpro.db;

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

public class CoolWeatherOpenHelper extends SQLiteOpenHelper {
	
	/**
	 *  Province表建表语句
	 */
	public static final String CREATE_PROVINCE = "create table Province ("
				+ "id integer primary key autoincrement, " 
				+ "province_name text, "
				+ "province_code text)";
	/**
	 *  City表建表语句
	 */
	public static final String CREATE_CITY = "create table City ("
				+ "id integer primary key autoincrement, " 
				+ "city_name text, " 
				+ "city_code text, " 
				+ "province_id integer)";
	/**
	 *  County表建表语句
	 */
	public static final String CREATE_COUNTY = "create table County ("
				+ "id integer primary key autoincrement, " 
				+ "county_name text, " 
				+ "county_code text, " 
				+ "city_id integer)";

	public CoolWeatherOpenHelper(Context context, String name, CursorFactory factory,
			int version) {
		super(context, name, factory, version);
	}

	@Override
	public void onCreate(SQLiteDatabase db) {
		db.execSQL(CREATE_PROVINCE);  // 创建Province表
		db.execSQL(CREATE_CITY);  // 创建City表
		db.execSQL(CREATE_COUNTY);  // 创建County表
	}

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

}

接下来就是操作数据库的方法了,在db包下,新建:CoolWeatherDB,本类是一个单例类,在开始数据库的操作之前,看看单例类:

/**
	 * 数据库名
	 */
	public static final String DB_NAME = "cool_weather";

	/**
	 * 数据库版本
	 */
	public static final int VERSION = 1;

	private static CoolWeatherDB coolWeatherDB;

	private SQLiteDatabase db;

	/**
	 * 将构造方法私有化
	 */
	private CoolWeatherDB(Context context) {
		CoolWeatherOpenHelper dbHelper = new CoolWeatherOpenHelper(context,
				DB_NAME, null, VERSION);
		db = dbHelper.getWritableDatabase();
	}

	/**
	 * 获取CoolWeatherDB的实例。
	 */
	public synchronized static CoolWeatherDB getInstance(Context context) {
		if (coolWeatherDB == null) {
			coolWeatherDB = new CoolWeatherDB(context);
		}
		return coolWeatherDB;
	}

在构造器中,指定了数据库的名称,游标工厂一般为null,数据库的版本。并通过CoolWeatherOpenHelper对象的getWritableDatabase得到SQLiteDatabase,接下来的数据库的insert等等操作,均需要SQLiteDatabase对象来完成。在获取CoolWeatherDB的实例的代码中,使用了synchronized,他保证了两个线程不会同时进入这个方法,这个方法变成了同步方法,解决了多线程的问题(这个也有问题的)。

接下来的操作针对省市县:

1.将省市县实例存储到数据库;

2.从数据库读取省市县的信息;

/**
	 * 将Province实例存储到数据库。
	 */
	public void saveProvince(Province province) {
		if (province != null) {
			ContentValues values = new ContentValues();
			values.put("province_name", province.getProvinceName());
			values.put("province_code", province.getProvinceCode());
			db.insert("Province", null, values);
		}
	}

	/**
	 * 从数据库读取全国所有的省份信息。
	 */
	public List<Province> loadProvinces() {
		List<Province> list = new ArrayList<Province>();
		Cursor cursor = db
				.query("Province", null, null, null, null, null, null);
		if (cursor.moveToFirst()) {
			do {
				Province province = new Province();
				province.setId(cursor.getInt(cursor.getColumnIndex("id")));
				province.setProvinceName(cursor.getString(cursor
						.getColumnIndex("province_name")));
				province.setProvinceCode(cursor.getString(cursor
						.getColumnIndex("province_code")));
				list.add(province);
			} while (cursor.moveToNext());
		}
		return list;
	}

	/**
	 * 将City实例存储到数据库。
	 */
	public void saveCity(City city) {
		if (city != null) {
			ContentValues values = new ContentValues();
			values.put("city_name", city.getCityName());
			values.put("city_code", city.getCityCode());
			values.put("province_id", city.getProvinceId());
			db.insert("City", null, values);
		}
	}

	/**
	 * 从数据库读取某省下所有的城市信息。
	 */
	public List<City> loadCities(int provinceId) {
		List<City> list = new ArrayList<City>();
		Cursor cursor = db.query("City", null, "province_id = ?",
				new String[] { String.valueOf(provinceId) }, null, null, null);
		if (cursor.moveToFirst()) {
			do {
				City city = new City();
				city.setId(cursor.getInt(cursor.getColumnIndex("id")));
				city.setCityName(cursor.getString(cursor
						.getColumnIndex("city_name")));
				city.setCityCode(cursor.getString(cursor
						.getColumnIndex("city_code")));
				city.setProvinceId(provinceId);
				list.add(city);
			} while (cursor.moveToNext());
		}
		return list;
	}

	/**
	 * 将County实例存储到数据库。
	 */
	public void saveCounty(County county) {
		if (county != null) {
			ContentValues values = new ContentValues();
			values.put("county_name", county.getCountyName());
			values.put("county_code", county.getCountyCode());
			values.put("city_id", county.getCityId());
			db.insert("County", null, values);
		}
	}

	/**
	 * 从数据库读取某城市下所有的县信息。
	 */
	public List<County> loadCounties(int cityId) {
		List<County> list = new ArrayList<County>();
		Cursor cursor = db.query("County", null, "city_id = ?",
				new String[] { String.valueOf(cityId) }, null, null, null);
		if (cursor.moveToFirst()) {
			do {
				County county = new County();
				county.setId(cursor.getInt(cursor.getColumnIndex("id")));
				county.setCountyName(cursor.getString(cursor
						.getColumnIndex("county_name")));
				county.setCountyCode(cursor.getString(cursor
						.getColumnIndex("county_code")));
				county.setCityId(cityId);
				list.add(county);
			} while (cursor.moveToNext());
		}
		return list;
	}

完整的代码:

package com.dy.ustc.weatherpro.db;

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

import com.dy.ustc.weatherpro.model.City;
import com.dy.ustc.weatherpro.model.County;
import com.dy.ustc.weatherpro.model.Province;

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

public class CoolWeatherDB {

	/**
	 * 数据库名
	 */
	public static final String DB_NAME = "cool_weather";

	/**
	 * 数据库版本
	 */
	public static final int VERSION = 1;

	private static CoolWeatherDB coolWeatherDB;

	private SQLiteDatabase db;

	/**
	 * 将构造方法私有化
	 */
	private CoolWeatherDB(Context context) {
		CoolWeatherOpenHelper dbHelper = new CoolWeatherOpenHelper(context,
				DB_NAME, null, VERSION);
		db = dbHelper.getWritableDatabase();
	}

	/**
	 * 获取CoolWeatherDB的实例。
	 */
	public synchronized static CoolWeatherDB getInstance(Context context) {
		if (coolWeatherDB == null) {
			coolWeatherDB = new CoolWeatherDB(context);
		}
		return coolWeatherDB;
	}

	/**
	 * 将Province实例存储到数据库。
	 */
	public void saveProvince(Province province) {
		if (province != null) {
			ContentValues values = new ContentValues();
			values.put("province_name", province.getProvinceName());
			values.put("province_code", province.getProvinceCode());
			db.insert("Province", null, values);
		}
	}

	/**
	 * 从数据库读取全国所有的省份信息。
	 */
	public List<Province> loadProvinces() {
		List<Province> list = new ArrayList<Province>();
		Cursor cursor = db
				.query("Province", null, null, null, null, null, null);
		if (cursor.moveToFirst()) {
			do {
				Province province = new Province();
				province.setId(cursor.getInt(cursor.getColumnIndex("id")));
				province.setProvinceName(cursor.getString(cursor
						.getColumnIndex("province_name")));
				province.setProvinceCode(cursor.getString(cursor
						.getColumnIndex("province_code")));
				list.add(province);
			} while (cursor.moveToNext());
		}
		return list;
	}

	/**
	 * 将City实例存储到数据库。
	 */
	public void saveCity(City city) {
		if (city != null) {
			ContentValues values = new ContentValues();
			values.put("city_name", city.getCityName());
			values.put("city_code", city.getCityCode());
			values.put("province_id", city.getProvinceId());
			db.insert("City", null, values);
		}
	}

	/**
	 * 从数据库读取某省下所有的城市信息。
	 */
	public List<City> loadCities(int provinceId) {
		List<City> list = new ArrayList<City>();
		Cursor cursor = db.query("City", null, "province_id = ?",
				new String[] { String.valueOf(provinceId) }, null, null, null);
		if (cursor.moveToFirst()) {
			do {
				City city = new City();
				city.setId(cursor.getInt(cursor.getColumnIndex("id")));
				city.setCityName(cursor.getString(cursor
						.getColumnIndex("city_name")));
				city.setCityCode(cursor.getString(cursor
						.getColumnIndex("city_code")));
				city.setProvinceId(provinceId);
				list.add(city);
			} while (cursor.moveToNext());
		}
		return list;
	}

	/**
	 * 将County实例存储到数据库。
	 */
	public void saveCounty(County county) {
		if (county != null) {
			ContentValues values = new ContentValues();
			values.put("county_name", county.getCountyName());
			values.put("county_code", county.getCountyCode());
			values.put("city_id", county.getCityId());
			db.insert("County", null, values);
		}
	}

	/**
	 * 从数据库读取某城市下所有的县信息。
	 */
	public List<County> loadCounties(int cityId) {
		List<County> list = new ArrayList<County>();
		Cursor cursor = db.query("County", null, "city_id = ?",
				new String[] { String.valueOf(cityId) }, null, null, null);
		if (cursor.moveToFirst()) {
			do {
				County county = new County();
				county.setId(cursor.getInt(cursor.getColumnIndex("id")));
				county.setCountyName(cursor.getString(cursor
						.getColumnIndex("county_name")));
				county.setCountyCode(cursor.getString(cursor
						.getColumnIndex("county_code")));
				county.setCityId(cityId);
				list.add(county);
			} while (cursor.moveToNext());
		}
		return list;
	}

}

测试框架的引入,新建一个test包,在该包下新建一个类TestDBCase继承自:AndroidTestCase。在AndroidMnifest.xml中引入一下的内容:



targetPackage为自己的包名。

首先测试数据库是否能够创建。

public class TestDBCase extends AndroidTestCase {
	
	/**
	 * 数据库名
	 */
	public static final String DB_NAME = "cool_weather";

	/**
	 * 数据库版本
	 */
	public static final int VERSION = 1;
	/**
	 * 测试创建数据库
	 * 
	 */
	public void testDB(){
		CoolWeatherOpenHelper helper = new CoolWeatherOpenHelper(getContext(), DB_NAME, null, VERSION);
		helper.getWritableDatabase();
	}
	
	
	
	

}




data/data/包名/database下导出数据库,使用SQLite expert打开:



ok,创建数据库搞定。

测试saveProvince方法:

public void saveProvince(){
		CoolWeatherDB db = CoolWeatherDB.getInstance(getContext());
		Province province = new Province();
		province.setProvinceName("安徽");
		province.setProvinceName("四川");
		province.setProvinceCode("22");
		province.setProvinceCode("27");
		db.saveProvince(province);
	}

导出数据库:



测试loadProvinces方法:

public void loadProvinces(){
		CoolWeatherDB db = CoolWeatherDB.getInstance(getContext());
		List<Province> provinces = db.loadProvinces();
		for (Province province : provinces) {
			System.out.println(province.toString());
		}
	}

看到打印的结果:




其他的市级和县级的类似。

本节数据库到此完毕。将代码提交到github上。





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