android.database.sqlite.SQLiteDatabase#create ( )源码实例Demo

@Override
public SQLiteDatabase getWritableDatabase() {
    SQLiteDatabase db;
    try {
        return super.getWritableDatabase();
    } catch(SQLiteException e) {
        try {
            db = SQLiteDatabase.openOrCreateDatabase(VLCApplication.getAppContext().getDatabasePath(DB_NAME), null);
        } catch(SQLiteException e2) {
            Log.w(TAG, "SQLite database could not be created! Media library cannot be saved.");
            db = SQLiteDatabase.create(null);
        }
    }
    int version = db.getVersion();
    if (version != DB_VERSION) {
        db.beginTransaction();
        try {
            if (version == 0) {
                onCreate(db);
            } else {
                onUpgrade(db, version, DB_VERSION);
            }
            db.setVersion(DB_VERSION);
            db.setTransactionSuccessful();
        } finally {
            db.endTransaction();
        }
    }
    return db;
}
 

protected SQLiteDatabase createDatabase()
{
    if (inMemory)
    {
        return SQLiteDatabase.create(null);
    } else
    {
        getContext().deleteDatabase("greendao-unittest-db.temp");
        return getContext().openOrCreateDatabase("greendao-unittest-db.temp", 0, null);
    }
}
 

public static AndroidSQLite open(File path) {
    SQLiteDatabase db;
    if (path != null) {
        db = SQLiteDatabase.openOrCreateDatabase(path, null);
    } else {
        db = SQLiteDatabase.create(null);
    }
    return new AndroidSQLite(db);
}
 

/**
 * Create and/or open a database that will be used for reading and writing.
 * The first time this is called, the database will be opened and
 * {@link #onCreate}, {@link #onUpgrade} and/or {@link #onOpen} will be
 * called.
 *
 * <p>Once opened successfully, the database is cached, so you can
 * call this method every time you need to write to the database.
 * (Make sure to call {@link #close} when you no longer need the database.)
 * Errors such as bad permissions or a full disk may cause this method
 * to fail, but future attempts may succeed if the problem is fixed.</p>
 *
 * <p class="caution">Database upgrade may take a long time, you
 * should not call this method from the application main thread, including
 * from {@link android.content.ContentProvider#onCreate ContentProvider.onCreate()}.
 *
 * @throws SQLiteException if the database cannot be opened for writing
 * @return a read/write database object valid until {@link #close} is called
 */
public synchronized SQLiteDatabase getWritableDatabase() {
    if (mDatabase != null && mDatabase.isOpen() && !mDatabase.isReadOnly()) {
        return mDatabase;  // The database is already open for business
    }

    if (mIsInitializing) {
        throw new IllegalStateException("getWritableDatabase called recursively");
    }

    boolean success = false;
    SQLiteDatabase db = null;

    try {
        mIsInitializing = true;
        if (mPath == null) {
            db = SQLiteDatabase.create(null);
        } else {
            db = mContext.openOrCreateDatabase(mPath.getName(), 0, mFactory);
        }

        int version = db.getVersion();
        if (version != mNewVersion) {
            db.beginTransaction();
            try {
                if (version == 0) {
                    onCreate(db);
                } else {
                    if (version > mNewVersion) {
                        LOG.warn("Can't downgrade read-only database from version " +
                                version + " to " + mNewVersion + ": " + db.getPath());
                    }
                    onUpgrade(db, version, mNewVersion);
                }
                db.setVersion(mNewVersion);
                db.setTransactionSuccessful();
            } finally {
                db.endTransaction();
            }
        }

        onOpen(db);
        success = true;
        return db;
    } finally {
        mIsInitializing = false;
        if (success) {
            if (mDatabase != null) {
                try { mDatabase.close(); } catch (Exception e) { }
            }
            mDatabase = db;
        } else {
            if (db != null) db.close();
        }
    }
}
 

/**
 * Create and/or open a database that will be used for reading and writing.
 * Once opened successfully, the database is cached, so you can call this
 * method every time you need to write to the database.  Make sure to call
 * {@link #close} when you no longer need it.
 *
 * <p>Errors such as bad permissions or a full disk may cause this operation
 * to fail, but future attempts may succeed if the problem is fixed.</p>
 *
 * @throws SQLiteException if the database cannot be opened for writing
 * @return a read/write database object valid until {@link #close} is called
 */
public synchronized SQLiteDatabase getWritableDatabase() {
    if (mDatabase != null && mDatabase.isOpen() && !mDatabase.isReadOnly()) {
        return mDatabase;  // The database is already open for business
    }

    if (mIsInitializing) {
        throw new IllegalStateException("getWritableDatabase called recursively");
    }

    // If we have a read-only database open, someone could be using it
    // (though they shouldn't), which would cause a lock to be held on
    // the file, and our attempts to open the database read-write would
    // fail waiting for the file lock.  To prevent that, we acquire the
    // lock on the read-only database, which shuts out other users.

    boolean success = false;
    SQLiteDatabase db = null;
    try {
        mIsInitializing = true;
        if (mName == null) {
            db = SQLiteDatabase.create(null);
        } else {
        	String path = databaseDirectory(mContext) + File.separator + mName;
        	db = SQLiteDatabase.openDatabase(path, mFactory, SQLiteDatabase.CREATE_IF_NECESSARY | SQLiteDatabase.NO_LOCALIZED_COLLATORS);
        }

        int version = db.getVersion();
        if (version != mNewVersion) {
            db.beginTransaction();
            try {
                if (version == 0) {
                    onCreate(db);
                } else {
                    onUpgrade(db, version, mNewVersion);
                }
                db.setVersion(mNewVersion);
                db.setTransactionSuccessful();
            } finally {
                db.endTransaction();
            }
        }

        onOpen(db);
        success = true;
        return db;
    } finally {
        mIsInitializing = false;
        if (success) {
            if (mDatabase != null) {
                try { mDatabase.close(); } catch (Exception e) { }
            }
            mDatabase = db;
        } else {
            if (db != null) db.close();
        }
    }
}