我正在尝试使用SQLite在Android Studio中的同一数据库中创建第二个表。但是，我不断得到一个表未找到错误，并认为它可能与错误的SQL代码有关。
我的数据库助手如下：
package com.example.katkin.stressguard;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import java.sql.SQLException;
public class DatabaseHelper extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "stressGuard.db";
private static final String TABLE_NAME = "users";
private static final String COLUMN_ID = "user_id";
private static final String COLUMN_USER = "username";
private static final String COLUMN_PASS = "password";
SQLiteDatabase db;
private static final String TABLE_CREATE = "create table users (user_id integer primary key not null , " +
"username text not null , password text not null);";
private static final String TABLE_NAME_MOOD_RATINGS = "mood_ratings";
private static final String TABLE_CREATE_MOOD_RATINGS = "create table mood_ratings (mood_rating_id integer primary key not null , " +
"mood_rating real not null , minutes_exercise integer not null , hours_slept integer not null , month_key integer not null , " +
"FOREIGN KEY(user_id) REFERENCES users(user_id));";
private static final String COLUMN_MOOD_RATING = "mood_rating";
private static final String COLUMN_EXERCISE = "minutes_exercise";
private static final String MOOD_RATING_COLUMN_ID = "mood_rating_id";
private static final String COLUMN_HOURS_SLEPT = "hours_slept";
private static final String COLUMN_MONTH_KEY = "month_key";
public DatabaseHelper(Context context) {
super(context , DATABASE_NAME , null , DATABASE_VERSION);
}
public void insertUser(Users u) {
db = this.getWritableDatabase();
ContentValues values = new ContentValues();
String query = "select * from users";
Cursor cursor = db.rawQuery(query , null);
int count = cursor.getCount();
values.put(COLUMN_ID , count);
values.put(COLUMN_USER , u.getUsername());
values.put(COLUMN_PASS , u.getPassword());
db.insert(TABLE_NAME, null, values);
db.close();
}
public String searchPass(String username) {
db = this.getReadableDatabase();
String query = "select username, password from " + TABLE_NAME;
Cursor cursor = db.rawQuery(query , null);
String uname, pword;
pword ="not found";
if(cursor.moveToFirst()) {
do {
uname = cursor.getString(0);
if (uname.equals(username)) {
pword = cursor.getString(1);
break;
}
} while(cursor.moveToNext());
}
return pword;
}
public void insertMoodRating(MoodRatings moodRating) {
db = this.getWritableDatabase();
ContentValues values = new ContentValues();
String query = "select * from mood_ratings";
Cursor cursor = db.rawQuery(query , null);
int count = cursor.getCount();
values.put(MOOD_RATING_COLUMN_ID , count);
values.put(COLUMN_MOOD_RATING , moodRating.getMoodRating());
values.put(COLUMN_HOURS_SLEPT , moodRating.getHoursSlept());
values.put(COLUMN_MONTH_KEY , moodRating.getMonthKey());
values.put(COLUMN_EXERCISE , moodRating.getMinutesExercise());
db.insert(TABLE_NAME, null, values);
db.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
//create user table
//create mood ratings table
db.execSQL(TABLE_CREATE);
try {
db.execSQL(TABLE_CREATE_MOOD_RATINGS);
} catch (Exception e) {
e.printStackTrace();
}
this.db = db;
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
String query = "DROP TABLE IF EXISTS " + TABLE_NAME;
db.execSQL(query);
String q2 = "DROP TABLE IF EXISTS " + TABLE_NAME_MOOD_RATINGS;
db.execSQL(q2);
this.onCreate(db);
}
}
这是调用它的方法：
public void saveButtonClick(View v) {
NumberPicker monthSelector = (NumberPicker) findViewById(R.id.monthSelector);
int monthKey = monthSelector.getValue();
//get ratings from mood rating bar
float moodRating = moodRatingBar.getRating();
//get ratings from wellbeing rating bar
NumberPicker exerciseNumberPicker = (NumberPicker) findViewById(R.id.minutesExercisedNumberPicker);
int minutesExercised = exerciseNumberPicker.getValue();
NumberPicker numberPicker = (NumberPicker) findViewById(R.id.timeSleptNumberPicker);
int timeSlept = numberPicker.getValue();
//insert details in database
MoodRatings moodRecord = new MoodRatings();
moodRecord.setMoodRating(moodRating);
moodRecord.setHoursSlept(timeSlept);
moodRecord.setMinutesExercise(minutesExercised);
moodRecord.setMonthKey(monthKey);
//moodRecord.setPassword(passwordString);
helper.insertMoodRating(moodRecord);
}
这是db类：
public class MoodRatings {
private int entry_id;
private float mood_rating;
//private float wellbeingRating;
private int minutes_exercise;
private int hours_slept;
private int month_key;
public MoodRatings() {
}
public MoodRatings(int entry_id, float mood_rating, int minutes_exercise, int month_key, int hours_slept) {
this.entry_id = entry_id;
this.mood_rating = mood_rating;
this.minutes_exercise = minutes_exercise;
this.month_key = month_key;
this.hours_slept = hours_slept;
}
public MoodRatings(float mood_rating, int minutes_exercise, int month_key, int hours_slept) {
this.mood_rating = mood_rating;
this.minutes_exercise = minutes_exercise;
this.month_key = month_key;
this.hours_slept = hours_slept;
}
public void setMoodRating(float mood_rating) {
this.mood_rating = mood_rating;
}
public float getMoodRating() {
return this.mood_rating;
}
public void setMonthKey(int month_key) {
this.month_key = month_key;
}
public int getMonthKey() {
return this.month_key;
}
public void setMinutesExercise(int minutes_exercise) {
this.minutes_exercise = minutes_exercise;
}
public int getMinutesExercise() {
return this.minutes_exercise;
}
public void setHoursSlept(int hours_slept) {
this.hours_slept = hours_slept;
}
public int getHoursSlept() {
return this.hours_slept;
}
}
这就是logcat，即使在包含try-catch块之后也似乎没有任何洞察力：
11-09 00:35:40.580 1878-1897/com.example.katkin.stressguard
W/EGL_emulation﹕ eglSurfaceAttrib not implemented
11-09 00:35:40.580 1878-1897/com.example.katkin.stressguard W/OpenGLRenderer﹕ Failed to set EGL_SWAP_BEHAVIOR on surface 0x7f1874eff680, error=EGL_SUCCESS
11-09 00:35:48.870 1878-1897/com.example.katkin.stressguard W/EGL_emulation﹕ eglSurfaceAttrib not implemented
11-09 00:35:48.870 1878-1897/com.example.katkin.stressguard W/OpenGLRenderer﹕ Failed to set EGL_SWAP_BEHAVIOR on surface 0x7f18762f2b00, error=EGL_SUCCESS
11-09 00:35:53.720 1878-1878/com.example.katkin.stressguard I/Choreographer﹕ Skipped 294 frames! The application may be doing too much work on its main thread.
11-09 00:36:04.960 1878-1897/com.example.katkin.stressguard W/EGL_emulation﹕ eglSurfaceAttrib not implemented
11-09 00:36:04.960 1878-1897/com.example.katkin.stressguard W/OpenGLRenderer﹕ Failed to set EGL_SWAP_BEHAVIOR on surface 0x7f1874eef440, error=EGL_SUCCESS
11-09 00:36:09.030 1878-1878/com.example.katkin.stressguard E/SQLiteLog﹕ (1) no such table: mood_ratings
11-09 00:36:09.030 1878-1878/com.example.katkin.stressguard D/AndroidRuntime﹕ Shutting down VM
--------- beginning of crash
11-09 00:36:09.030 1878-1878/com.example.katkin.stressguard E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.katkin.stressguard, PID: 1878
java.lang.IllegalStateException: Could not execute method of the activity
at android.view.View$1.onClick(View.java:4007)
at android.view.View.performClick(View.java:4756)
at android.view.View$PerformClick.run(View.java:19749)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.view.View$1.onClick(View.java:4002)
at android.view.View.performClick(View.java:4756)
at android.view.View$PerformClick.run(View.java:19749)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: android.database.sqlite.SQLiteException: no such table: mood_ratings (code 1): , while compiling: select * from mood_ratings
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:889)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:500)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1316)
at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1255)
at com.example.katkin.stressguard.DatabaseHelper.insertMoodRating(DatabaseHelper.java:87)
at com.example.katkin.stressguard.MoodDiary.saveButtonClick(MoodDiary.java:106)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.view.View$1.onClick(View.java:4002)
at android.view.View.performClick(View.java:4756)
at android.view.View$PerformClick.run(View.java:19749)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
我是Android的新手，所以怀疑我错过了一些非常明显的东西。任何帮助，将不胜感激！第一个用户表工作并插入数据，第二个心情评级表没有。
答案 0 :(得分：0)
如果您已将数据库添加到数据库中，则需要告诉android重建它。增加数据库版本，或手动删除它（可能通过清除应用程序数据）