我的 sql 数据库有问题。
我正在使用现有的 sql 数据库，但程序没有读取它。
我的sql表如下：
BEGIN TRANSACTION;
CREATE TABLE "android_metadata" ("locale" TEXT DEFAULT 'en_US');
INSERT INTO android_metadata VALUES('en_US');
CREATE TABLE bucketitems (
"_id" INTEGER PRIMARY KEY NOT NULL,
"bucketNo" INTEGER NOT NULL,
"bucketItemName" TEXT NOT NULL,
"bucketItemImg" TEXT,
"bucketItemDesc" TEXT,
"completed" INTEGER NOT NULL
);
INSERT INTO bucketitems VALUES(1,1,'Test',NULL,NULL,0);
COMMIT;
我将 sql 文件放在资产文件夹中。
然后使用此代码
public class DatabaseHandler extends SQLiteOpenHelper {
// Contacts table name
private static final String TABLE_BUCKET_ITEMS = "bucketitems";
// Contacts Table Columns names
private static final String KEY_ID = "_id";
private static final String KEY_BUCKET = "bucketNo";
private static final String KEY_NAME = "bucketItemName";
private static final String KEY_FLAG = "completed";
private static String DB_PATH = "/data/data/com.example.bucketlist/databases/";
private static String DB_NAME = "bucketList";
private SQLiteDatabase myDataBase;
private final Context myContext;
public DatabaseHandler(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
//Creates a empty database on the system and rewrites it with your own database.
public void createDataBase() throws IOException {
boolean dbExist = checkDataBase();
if (dbExist) {
} else {
this.getReadableDatabase();
try {
this.close();
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
// Check if the database already exist to avoid re-copying the file
private boolean checkDataBase() {
SQLiteDatabase checkDB = null;
try {
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READWRITE);
} catch (SQLiteException e) {
}
if (checkDB != null) {
checkDB.close();
}
return checkDB != null ? true : false;
}
// Copies your database from your local assets-folder to the just created
private void copyDataBase() throws IOException {
InputStream myInput = myContext.getAssets().open(DB_NAME);
String outFileName = DB_PATH + DB_NAME;
OutputStream myOutput = new FileOutputStream(outFileName);
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException {
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READWRITE);
}
@Override
public synchronized void close() {
if (myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_BUCKET_ITEMS);
onCreate(db);
}
// Getting All Contacts
public Bucket[] getAllContacts(int bucketNo) {
List<BucketItem> bucketList = new ArrayList<BucketItem>();
String selectQuery = "SELECT * FROM " + TABLE_BUCKET_ITEMS + " WHERE "
+ KEY_BUCKET + " = " + bucketNo;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
if (cursor.moveToFirst()) {
do {
BucketItem bucket = new BucketItem();
bucket.setBucketItemNo(Integer.parseInt(cursor.getString(0)));
bucket.setBucketItemName(cursor.getString(2));
Boolean isCompleted = false;
if (Integer.parseInt(cursor.getString(5)) == 0) {
isCompleted = true;
}
bucket.setCompleted(isCompleted);
bucketList.add(bucket);
} while (cursor.moveToNext());
}
Bucket[] buckets = bucketList.toArray(new Bucket[bucketList.size()]);
return buckets;
}
//Updating BucketItem
public int updateContact(BucketItem bucketItem) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, bucketItem.getBucketItemName());
values.put(KEY_FLAG, bucketItem.isCompleted());
// updating row
return db.update(TABLE_BUCKET_ITEMS, values, KEY_ID + " = ?",
new String[] { String.valueOf(bucketItem.getBucketItemNo()) });
}
然后在我的活动课上，我的代码如下。
@覆盖
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bucket_item);
int value = getIntent().getExtras().getInt("bucketno");
DatabaseHandler myDbHelper = new DatabaseHandler(this);
try {
myDbHelper.createDataBase();
} catch (IOException ioe) {
throw new Error("Unable to create database");
}
try {
myDbHelper.openDataBase();
}catch(SQLException sqle){
throw sqle;
}
Bucket[] buckets = myDbHelper.getAllContacts(value);
System.out.println(buckets);
}
但我有一个错误。
12-26 09:34:17.667: E/SQLiteLog(792): (1) no such table: bucketitems
12-26 09:34:24.030: D/AndroidRuntime(792): Shutting down VM
12-26 09:34:24.030: W/dalvikvm(792): threadid=1: thread exiting with uncaught exception (group=0x40a70930)
12-26 09:34:24.166: E/AndroidRuntime(792): FATAL EXCEPTION: main
12-26 09:34:24.166: E/AndroidRuntime(792): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.bucketlist/com.example.bucketlist.BucketItemActivity}: android.database.sqlite.SQLiteException: no such table: bucketitems (code 1): , while compiling: SELECT * FROM bucketitems WHERE bucketNo = 1
12-26 09:34:24.166: E/AndroidRuntime(792): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
12-26 09:34:24.166: E/AndroidRuntime(792): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
请帮忙。谢谢你。