Android
[Android] SQLite 이미 만들어진 DB 정보 불러오기
초비
2021. 5. 12. 10:45
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1. assets 폴더에 db파일 넣기
: db생성은 DB Browser 이용
2. SQLiteOpenHelper 클래스를 상속한 DataBaseHelper클래스안에서, assets 안에서 그 db파일을 복사하기
[DataBaseHelper class]
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package com.example.yummyfridge;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import androidx.annotation.Nullable;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class DataBaseHelper extends SQLiteOpenHelper{
private final static String TAG = "DataBaseHelper"; // Logcat에 출력할 태그이름
// database 의 파일 경로
private static String DB_PATH = "";
private static String DB_NAME = "recipe.db";
private SQLiteDatabase mDataBase;
private Context mContext;
public DataBaseHelper(Context context) {
super(context,DB_NAME,null,1);
DB_PATH = "/data/data/" + context.getPackageName() + "/databases/";
this.mContext = context;
dataBaseCheck();
}
private void dataBaseCheck() {
File dbFile = new File(DB_PATH + DB_NAME);
if (!dbFile.exists()) {
dbCopy();
Log.d(TAG,"Database is copied.");
}
}
@Override
public synchronized void close() {
if (mDataBase != null) {
mDataBase.close();
}
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
// 테이블 구조 생성로직
Log.d(TAG,"onCreate()");
}
@Override
public void onOpen(SQLiteDatabase db) {
super.onOpen(db);
//Toast.makeText(mContext,"onOpen()",Toast.LENGTH_SHORT).show();
Log.d(TAG,"onOpen() : DB Opening!");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// 테이블 삭제하고 onCreate() 다시 로드시킨다.
Log.d(TAG,"onUpgrade() : DB Schema Modified and Excuting onCreate()");
}
// db를 assets에서 복사해온다.
private void dbCopy() {
try {
File folder = new File(DB_PATH);
if (!folder.exists()) {
folder.mkdir();
}
InputStream inputStream = mContext.getAssets().open(DB_NAME);
String out_filename = DB_PATH + DB_NAME;
OutputStream outputStream = new FileOutputStream(out_filename);
byte[] mBuffer = new byte[1024];
int mLength;
while ((mLength = inputStream.read(mBuffer)) > 0) {
outputStream.write(mBuffer,0,mLength);
}
outputStream.flush();;
outputStream.close();
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
Log.d("dbCopy","IOException 발생함");
}
}
}
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3. DB 내용 불러오기
[MainActivity.java]
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public void getVal() {
DataBaseHelper dbHelper = new DataBaseHelper(this);
SQLiteDatabase db = dbHelper.getReadableDatabase();
Cursor cursor = db.rawQuery("SELECT * FROM recipe_ingredient where RECIPE_ID = 195453",null);
//" and name = ?",new String[]{"홍길동"});
while (cursor.moveToNext())
{
val += cursor.getString(2)+", ";
}
sqlresult.setText("재료: "+val);
cursor.close();
dbHelper.close();
}
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[참고]
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