让 SQLite 在我的 Android 应用程序中运行时遇到问题
https://stackoverflow.com//questions/20010029
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20-12-2019 - |
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我在让 SQLite 在我正在开发的 Android 应用程序中正常工作时遇到问题。似乎没有根据 LogCat 消息正确创建该表。我感觉我盯着屏幕看太久了。这里有人能发现我的代码中的问题吗？
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class DBHelper extends SQLiteOpenHelper {
// table name
public static final String TABLE_JOKES = "jokes";
// database field names
public static final String COLUMN_ID = "_id";
public static final String COLUMN_CATEGORY = "category";
public static final String COLUMN_SUBCATEGORY = "subcategory";
public static final String COLUMN_JOKE_TYPE = "jokeType";
public static final String COLUMN_DESCRIPTION = "description";
public static final String COLUMN_QUESTION_TEXT = "questionText";
public static final String COLUMN_ANSWER_TEXT = "answerText";
public static final String COLUMN_MONOLOGUE_TEXT = "monologueText";
public static final String COLUMN_RATING_SCALE = "ratingScale";
public static final String COLUMN_COMMENTS = "comments";
public static final String COLUMN_JOKE_SOURCE = "jokeSource";
public static final String COLUMN_RELEASE_STATUS = "releaseStatus";
public static final String COLUMN_CREATED = "created";
public static final String COLUMN_MODIFIED = "modified";
private static final String DATABASE_NAME = "jokes.db"; // file name
private static final int DATABASE_VERSION = 1;
// Database creation raw SQL statement
private static final String DATABASE_CREATE = "create table " + TABLE_JOKES
+ "( " + COLUMN_ID + " integer primary key autoincrement, "
+ COLUMN_CATEGORY + " text not null, " + COLUMN_SUBCATEGORY
+ " text not null, " + COLUMN_JOKE_TYPE + " integer not null, "
+ COLUMN_DESCRIPTION + " text," + COLUMN_QUESTION_TEXT + "text,"
+ COLUMN_ANSWER_TEXT + "text," + COLUMN_MONOLOGUE_TEXT + "text,"
+ COLUMN_RATING_SCALE + "integer," + COLUMN_COMMENTS + "text,"
+ COLUMN_JOKE_SOURCE + "text," + COLUMN_RELEASE_STATUS + "integer,"
+ COLUMN_CREATED + "text," + COLUMN_MODIFIED + "text" + ");";
// static instance to share DBHelper
private static DBHelper dbHelper = null;
private SQLiteDatabase db ;
/**
* Constructor
*
* @param context
* @param name
* @param factory
* @param version
*/
public DBHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
db = getWritableDatabase();
}
/**
* This is a static method that makes sure that only one database helper
* exists across the app's lifecycle
*
* @param context
* @return
*/
public static DBHelper getDBHelper(Context context) {
if (dbHelper == null) {
dbHelper = new DBHelper(context.getApplicationContext());
}
return dbHelper;
}
/*
* (non-Javadoc)
*
* @see
* android.database.sqlite.SQLiteOpenHelper#onCreate(android.database.sqlite
* .SQLiteDatabase)
*/
@Override
public void onCreate(SQLiteDatabase database) {
database.execSQL(DATABASE_CREATE);
}
/*
* (non-Javadoc)
*
* @see
* android.database.sqlite.SQLiteOpenHelper#onUpgrade(android.database.sqlite
* .SQLiteDatabase, int, int)
*/
@Override
public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) {
Log.w(DBHelper.class.getName(), "Upgrading database from version "
+ oldVersion + " to " + newVersion);
}
/**
* CRUD - Update
*
* @param category
* @param subcategory
* @param jokeType
* @param description
* @param questionText
* @param answerText
* @param monologueText
* @param comments
* @param jokeSource
* @param ratingScale
* @param releaseStatus
* @return
*/
public long insertNewJoke(String category, String subcategory,
int jokeType, String description, String questionText,
String answerText, String monologueText, String comments,
String jokeSource, int ratingScale, int releaseStatus) {
ContentValues cv = new ContentValues();
cv.put(COLUMN_CATEGORY, category);
cv.put(COLUMN_SUBCATEGORY, subcategory);
cv.put(COLUMN_JOKE_TYPE, jokeType);
cv.put(COLUMN_DESCRIPTION, description);
cv.put(COLUMN_QUESTION_TEXT, questionText);
cv.put(COLUMN_ANSWER_TEXT, answerText);
cv.put(COLUMN_MONOLOGUE_TEXT, monologueText);
cv.put(COLUMN_COMMENTS, comments);
cv.put(COLUMN_JOKE_SOURCE, jokeSource);
cv.put(COLUMN_RATING_SCALE, ratingScale);
cv.put(COLUMN_RELEASE_STATUS, releaseStatus);
cv.put(COLUMN_CREATED, ""); // how to put date??
cv.put(COLUMN_CREATED, "");
long code = getWritableDatabase().insert(TABLE_JOKES, null, cv);
return code;
}
/**
* CRUD - Retrieve
*
* @return
*/
public Cursor getJokes() {
String[] columns = { COLUMN_CATEGORY, COLUMN_SUBCATEGORY,
COLUMN_JOKE_TYPE, COLUMN_DESCRIPTION, COLUMN_ANSWER_TEXT,
COLUMN_MONOLOGUE_TEXT, COLUMN_RATING_SCALE, COLUMN_COMMENTS,
COLUMN_JOKE_SOURCE, COLUMN_RELEASE_STATUS, COLUMN_CREATED,
COLUMN_MODIFIED }; // might need the _id column
return getWritableDatabase().query(TABLE_JOKES, columns, null, null,
null, null, null);
}
/**
* CRUD - Delete
*
* @param id
*/
public void deleteJoke(int id) {
getWritableDatabase().delete(TABLE_JOKES, COLUMN_ID + "=?",
new String[] { String.valueOf(id) });
}
}
因此，在 onCreate() （在我的 MainActivity 中）中，我尝试将新记录插入数据库，然后尝试将其检索到游标中。然而，它似乎被插入语句所困扰。
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// the projection (fields from the database that we want to use)
String from[] = { DBHelper.COLUMN_DESCRIPTION };
// matching fields on the layout to be used with the adapter
int to[] = { R.id.tv1 };
setContentView(R.layout.activity_main);
lv = (ListView) findViewById(R.id.lvMainJokes);
dbHelper = DBHelper.getDBHelper(this);
long code = dbHelper.insertNewJoke("Holiday", "", 2, "Joke 1 Description", "", "",
"joke", "", "", 5, 1);
if (code != -1)
cursor = dbHelper.getJokes();
...
这是 LogCat 输出：
11-15 15:19:08.040: I/Choreographer(1016): Skipped 45 frames! The application may be doing too much work on its main thread.
11-15 15:19:35.358: D/dalvikvm(1064): GC_FOR_ALLOC freed 58K, 4% free 2726K/2836K, paused 42ms, total 45ms
11-15 15:19:35.368: I/dalvikvm-heap(1064): Grow heap (frag case) to 3.315MB for 635812-byte allocation
11-15 15:19:35.438: D/dalvikvm(1064): GC_FOR_ALLOC freed 2K, 4% free 3344K/3460K, paused 63ms, total 63ms
11-15 15:19:35.548: E/SQLiteLog(1064): (1) table jokes has no column named releaseStatus
11-15 15:19:35.568: E/SQLiteDatabase(1064): Error inserting category=Holiday releaseStatus=1 jokeType=2 created= monologueText=joke description=Joke 1 Description subcategory= answerText= questionText= jokeSource= ratingScale=5 comments=
11-15 15:19:35.568: E/SQLiteDatabase(1064): android.database.sqlite.SQLiteException: table jokes has no column named releaseStatus (code 1): , while compiling: INSERT INTO jokes(category,releaseStatus,jokeType,created,monologueText,description,subcategory,answerText,questionText,jokeSource,ratingScale,comments) VALUES (?,?,?,?,?,?,?,?,?,?,?,?)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:889)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:500)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1467)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1339)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at com.teamdotgetname.android.phase1.jokeapplication.persistence.DBHelper.insertNewJoke(DBHelper.java:143)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at com.teamdotgetname.android.phase1.jokeapplication.presentation.MainActivity.onCreate(MainActivity.java:53)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.app.Activity.performCreate(Activity.java:5133)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.app.ActivityThread.access$600(ActivityThread.java:141)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.os.Handler.dispatchMessage(Handler.java:99)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.os.Looper.loop(Looper.java:137)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at android.app.ActivityThread.main(ActivityThread.java:5103)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at java.lang.reflect.Method.invokeNative(Native Method)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at java.lang.reflect.Method.invoke(Method.java:525)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
11-15 15:19:35.568: E/SQLiteDatabase(1064): at dalvik.system.NativeStart.main(Native Method)
11-15 15:19:35.798: I/Choreographer(1064): Skipped 42 frames! The application may be doing too much work on its main thread.
11-15 15:19:35.868: D/gralloc_goldfish(1064): Emulator without GPU emulation detected.
谢谢参观。
解决方案
乍一看，您的代码看起来不错。例外情况：
android.database.sqlite.SQLiteException: table jokes has no column named releaseStatus (code 1)
似乎是错误的，因为显然你正在创建 releaseStatus 创建表中的列 DATABASE_CREATE 细绳。我遇到了一个问题，我正在修改数据库的架构，并且更改没有在我的应用程序中生效，因为我没有增加 DATABASE_VERSION.
您可以尝试的选项将导致数据库重新创建：
- 通过设置 apk 清除应用程序数据
- 手动卸载然后重新安装您的应用程序。（刚刚运行
gradle installDebug或者让 Eclipse 安装您的应用程序还不够好） - 增加你的
DATABASE_VERSION价值
其他提示
我会说你需要创建语句中的一些空格。 启动：column_question_text +“text，”tool_question_text +“text”。
它看起来就像你在列名和列类型之间没有空格。试试这个。
private static final String DATABASE_CREATE = "create table " + TABLE_JOKES
+ "( " + COLUMN_ID + " integer primary key autoincrement, "
+ COLUMN_CATEGORY + " text not null, " + COLUMN_SUBCATEGORY
+ " text not null, " + COLUMN_JOKE_TYPE + " integer not null, "
+ COLUMN_DESCRIPTION + " text," + COLUMN_QUESTION_TEXT + " text,"
+ COLUMN_ANSWER_TEXT + " text," + COLUMN_MONOLOGUE_TEXT + " text,"
+ COLUMN_RATING_SCALE + " integer," + COLUMN_COMMENTS + " text,"
+ COLUMN_JOKE_SOURCE + " text," + COLUMN_RELEASE_STATUS + " integer,"
+ COLUMN_CREATED + " text," + COLUMN_MODIFIED + " text" + ");";
在数据库中创建错误“整数”+列注释+“文本”。没有单独的空间。
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