在android中创建表Movie并对其进行管理，我已经编写了以下代码：
MovieDatabase.java
package com.example.msnma.movienotifier.database;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import com.example.msnma.movienotifier.MainActivity;
import com.example.msnma.movienotifier.databaseModel.MovieDBModel;
import com.example.msnma.movienotifier.databaseModel.TypeDBModel;
import com.example.msnma.movienotifier.mapper.MovieMapper;
import com.example.msnma.movienotifier.model.Movie;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Locale;
public class MovieDatabase extends SQLiteOpenHelper {
private static final String LOG = "DatabaseHelper";
private static final String DATABASE_NAME = "movieDatabase";
private static final int DATABASE_VERSION = 1;
//Table Names
private static final String TABLE_MOVIE = "MovieTable";
private static final String TABLE_TYPE = "TypeTable";
private static final String TABLE_MOVIE_TYPE = "MovieTypeTable";
//Table Fields
private static final String MOVIE_ID ="movie_id";
private static final String TITLE ="title";
private static final String OVERVIEW = "overview";
private static final String POSTER_URL = "posterUrl";
private static final String BACKDROP_URL = "backdropUrl";
private static final String TRAILER_URL = "trailerUrl";
private static final String RELEASE_DATE = "releaseDate";
private static final String RATING = "rating";
private static final String ADULT = "adult";
private static final String TYPE_ID = "type_id";
private static final String TYPE_DESCR = "type_descr";
private static final String MOVIE_TYPE_ID = "movie_type_id";
private static final String M_ID = "movie_id";
private static final String T_ID = "type_id";
private static final String notify_datetime = "notify_datetime";
// Table Create Statements
private static final String CREATE_TABLE_MOVIE = "CREATE TABLE "
+ TABLE_MOVIE + "(" + MOVIE_ID + " INTEGER PRIMARY KEY," + TITLE + " TEXT,"
+ OVERVIEW + " TEXT," + POSTER_URL + " TEXT," + BACKDROP_URL + " TEXT," + TRAILER_URL + " TEXT,"
+ RATING + " REAL," + ADULT + " INTEGER," + RELEASE_DATE + " DATETIME," + notify_datetime + " DATETIME" + ")";
// Tag table create statement
private static final String CREATE_TABLE_TYPE = "CREATE TABLE " + TABLE_TYPE
+ "(" + TYPE_ID + " INTEGER PRIMARY KEY," + TYPE_DESCR + " TEXT" + ")";
// todo_tag table create statement
private static final String CREATE_TABLE_MOVIE_TYPE = "CREATE TABLE "
+ TABLE_MOVIE_TYPE + "(" + MOVIE_TYPE_ID + " INTEGER PRIMARY KEY,"
+ M_ID + " INTEGER," + T_ID + " INTEGER" + ")";
SQLiteDatabase database;
public MovieDatabase(Context context){
super(context, DATABASE_NAME, null, DATABASE_VERSION);
database = getWritableDatabase();
}
@Override
public void onCreate(SQLiteDatabase db) {
// creating required tables
db.execSQL(CREATE_TABLE_MOVIE);
db.execSQL(CREATE_TABLE_TYPE);
db.execSQL(CREATE_TABLE_MOVIE_TYPE);
insertType(db); //NOTA: questo va chiamato solo la prima volta che instanziamo il DB, AGGIUNGERE CONTROLLO!
//in teoria onCreate verrà chiamato solo la prima volta...
}
@Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {
// on upgrade drop older tables
db.execSQL("DROP TABLE IF EXISTS " + TABLE_MOVIE);
db.execSQL("DROP TABLE IF EXISTS " + TABLE_TYPE);
db.execSQL("DROP TABLE IF EXISTS " + TABLE_MOVIE_TYPE);
// create new tables
onCreate(db);
}
//questa funzione serve solo per inserire casualmente dai suggested movies, alcuni notify e watched movies
public static void saveMoviesOnDB(List<Movie> movies, String type){
MovieDatabase db = MainActivity.getMovieDatabase();
MovieMapper mapper = new MovieMapper();
List<MovieDBModel> moviesDB = mapper.toMovieDBModelList(movies);
Integer typeId = 0;
int index = 0;
if(type.equals("notify")){
typeId = 1;
}else if(type.equals("watched")){
typeId = 2;
index = index+5;
}else{
//todo catch invalid type Id exception
}
for(int a = index; a<index+5; a++){
insertMovie(moviesDB.get(a), typeId, db);
}
}
//open the database, maybe not useful...
public MovieDatabase open() throws SQLException
{
database = getWritableDatabase();
return this;
}
// closing database
public void closeDB() {
SQLiteDatabase db = this.getReadableDatabase();
if (db != null && db.isOpen())
db.close();
}
//CRUDs
public static void insertMovie(MovieDBModel movie, Integer typeId, MovieDatabase db) {
SQLiteDatabase database = db.getWritableDatabase();
if(checkMovieUniqueness(movie.getTitle(), db)) { //NON VOGLIO INSERIRE PIù VOLTE LO STESSO FILM
ContentValues values = new ContentValues();
values.put(TITLE, movie.getTitle());
values.put(OVERVIEW, movie.getOverview());
values.put(POSTER_URL, movie.getPosterUrl());
values.put(BACKDROP_URL, movie.getBackdropUrl());
values.put(TRAILER_URL, movie.getTrailerUrl());
values.put(RELEASE_DATE, movie.getReleaseDate().toString());
values.put(RATING, movie.getRating());
values.put(ADULT, movie.isAdult());
//inizio nuovo codice
if(typeId == 1) {
values.put(notify_datetime, movie.getNotifyDate().toString());
Log.i("TYPEID", "Siamo dentro");
}
//else values.putNull(NOTIFY_TIME_DATE);
//fine nuovo codice
// insert row
long movieId = database.insert(TABLE_MOVIE, null, values);
insertMovieType(movieId, typeId, db);
}
}
public static void insertMovieType(Long movieId, Integer typeId, MovieDatabase db){
SQLiteDatabase database = db.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(M_ID, movieId.intValue());
values.put(T_ID, typeId);
database.insert(TABLE_MOVIE_TYPE, null, values);
}
private void insertType(SQLiteDatabase db){
ContentValues descr1 = new ContentValues();
descr1.put(TYPE_DESCR, "NOTIFY");
ContentValues descr2 = new ContentValues();
descr2.put(TYPE_DESCR, "WATCHED");
// insert row
db.insert(TABLE_TYPE, null, descr1);
db.insert(TABLE_TYPE, null, descr2);
}
private TypeDBModel getTypeByTypeDescr(String typeDescr) {
SQLiteDatabase db = this.getReadableDatabase();
String selectQuery = "SELECT * FROM " + TABLE_TYPE + " WHERE "
+ TYPE_DESCR + " = " + typeDescr;
Log.e(LOG, selectQuery);
Cursor c = db.rawQuery(selectQuery, null);
if (c != null)
c.moveToFirst();
TypeDBModel td = new TypeDBModel();
td.setId(c.getInt(c.getColumnIndex(TYPE_ID)));
td.setDescription((c.getString(c.getColumnIndex(TYPE_DESCR))));
return td;
}
private static boolean checkMovieUniqueness(String movieTitle, MovieDatabase db) {
SQLiteDatabase database = db.getReadableDatabase();
String selectQuery = "SELECT * FROM " + TABLE_MOVIE + " WHERE "
+ TITLE + " = " + "'"+ movieTitle + "'";
Log.e(LOG, selectQuery);
Cursor c = database.rawQuery(selectQuery, null);
if(c.moveToFirst()){
c.close();
return false;
}else{
c.close();
return true;
}
}
public List<MovieDBModel> getAllMovieByType(String typeDescr) throws ParseException {
List<MovieDBModel> movies = new ArrayList<MovieDBModel>();
String selectQuery = "SELECT * FROM " + TABLE_MOVIE + " mv, "
+ TABLE_TYPE + " type, " + TABLE_MOVIE_TYPE + " tmt WHERE type."
+ TYPE_DESCR + " = '" + typeDescr + "'" + " AND type." + TYPE_ID
+ " = " + "tmt." + T_ID + " AND mv." + MOVIE_ID + " = "
+ "tmt." + M_ID;
Log.e(LOG, selectQuery);
SQLiteDatabase db = this.getReadableDatabase();
Cursor c = db.rawQuery(selectQuery, null);
SimpleDateFormat sdf3 = new SimpleDateFormat("EEE MMM dd HH:mm:ss zzz yyyy", Locale.ENGLISH);
// looping through all rows and adding to list
if (c.moveToFirst()) {
do {
MovieDBModel td = new MovieDBModel();
td.setId(c.getInt((c.getColumnIndex(MOVIE_ID))));
td.setTitle((c.getString(c.getColumnIndex(TITLE))));
td.setOverview(c.getString(c.getColumnIndex(OVERVIEW)));
td.setPosterUrl(c.getString((c.getColumnIndex(POSTER_URL))));
td.setBackdropUrl((c.getString(c.getColumnIndex(BACKDROP_URL))));
td.setTrailerUrl(c.getString(c.getColumnIndex(TRAILER_URL)));
String dateString =c.getString((c.getColumnIndex(RELEASE_DATE)));
Date date = sdf3.parse(dateString);
td.setReleaseDate(date);
td.setRating((c.getFloat(c.getColumnIndex(RATING))));
int adult = c.getInt(c.getColumnIndex(ADULT));
if(adult == 0){
td.setAdult(true); //NOT sure if is the contrary
}else{
td.setAdult(false);
}
movies.add(td);
} while (c.moveToNext());
}
return movies;
}
public void deleteMovie(long tado_id) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_MOVIE, MOVIE_ID + " = ?",
new String[] { String.valueOf(tado_id) });
}
public void deleteMovieType(long tado_id) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_MOVIE_TYPE, M_ID + " = ?",
new String[] { String.valueOf(tado_id) });
}
public int updateMovieType(long id, long tag_id) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(T_ID, tag_id);
// updating row
return db.update(TABLE_MOVIE_TYPE, values, M_ID + " = ?",
new String[] { String.valueOf(id) });
}
}
现在，当应用程序运行时，我的日志中出现以下错误：
2018-08-27 23:08:02.336 3786-3786/com.example.msnma.movienotifier E/SQLiteDatabase: Error inserting rating=7.0 title=Crazy Rich Asians notify_datetime=Thu Sep 27 09:30:00 GMT+02:00 2018 posterUrl=https://image.tmdb.org/t/p/w185/gnTqi4nhIi1eesT5uYMmhEPGNih.jpg releaseDate=Wed Aug 15 00:00:00 GMT+02:00 2018 adult=false trailerUrl=https://youtube.com/watch?v=PI5mBzQ1Iok overview=An American-born Chinese economics professor accompanies her boyfriend to Singapore for his best friend's wedding, only to get thrust into the lives of Asia's rich and famous. backdropUrl=https://image.tmdb.org/t/p/w300/zeHB7aP46Xs3u4aFLuAq2GFeUGb.jpg
android.database.sqlite.SQLiteException: table MovieTable has no column named notify_datetime (Sqlite code 1): , while compiling: INSERT INTO MovieTable(rating,title,notify_datetime,posterUrl,releaseDate,adult,trailerUrl,overview,backdropUrl) VALUES (?,?,?,?,?,?,?,?,?), (OS error - 2:No such file or directory)
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:910)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:521)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:603)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:63)
at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1725)
at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1593)
at com.example.msnma.movienotifier.database.MovieDatabase.insertMovie(MovieDatabase.java:151)
at com.example.msnma.movienotifier.adapter.MoviesAdapter$7.onClick(MoviesAdapter.java:378)
at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166)
at android.os.Handler.dispatchMessage(Handler.java:105)
at android.os.Looper.loop(Looper.java:156)
at android.app.ActivityThread.main(ActivityThread.java:6523)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:942)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:832)
实际上，我的最后一列名为 notify_datetimeDATETIME ，而不是 notifify_datetime
似乎用notify_datetime + " DATETIME"连接两个字符串
我该怎么办才能解决问题？
答案 0 :(得分：2)
如果您尚未发布该应用程序，则只需更改该列的名称，然后重新安装即可。但是，一旦发布该应用程序，您将必须增加数据库版本号，然后覆盖onUpgrade。通过这种方法，您可以检查旧版本是否小于最新版本，并相应地修改表，如果数据可能丢失，则只需删除并重新创建表，如果不能丢失，则使用alter table语句。
例如
private static final int DATABASE_VERSION = 2;
private static final int DATABASE_NAME = "myDb.sqlite";
private DatabaseOpenHelper(Context context, SharedPrefsContract.Manager sharedPrefsManager) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if (oldVersion < 2) {
// There is where you alter the table
}
}
更改表格
首先，您将旧表重命名：
ALTER TABLE orig_table_name RENAME TO tmp_table_name;
然后基于旧表创建新表，但使用更新的列名：
CREATE TABLE orig_table_name (
col_a INT
, col_b INT
);
然后将内容复制到原始表中。
INSERT INTO orig_table_name(col_a, col_b)
SELECT col_a, colb
FROM tmp_table_name;
最后，放下旧桌子。
DROP TABLE tmp_table_name;
将所有内容包装在BEGIN TRANSACTION;和COMMIT;中也是一个好主意。
答案 1 :(得分：1)
您尝试删除应用，在设备上重新运行或增加DATABASE_VERSION。因为数据库存在时无法重新创建。