Question

我正在使用现有数据库在Android应用中构建数据库。我在调试中继续收到错误，说列stop_name不存在：

    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.bkane56.practice.practiceapp/com.bkane56.practice.practiceapp.MainActivity}: java.lang.IllegalArgumentException: column '_id' does not exist

数据库的架构如下：

CREATE TABLE trips (
    block_id char(40),
    route_id char(40),
    direction_id char(2),
    trip_headsign char(20),
    shape_id char(20),
    service_id char(20),
    _id char(20) PRIMARY KEY,
    FOREIGN KEY(route_id) references routes(_id),
    FOREIGN KEY(service_id) references calendar(_id)
);
CREATE TABLE calendar(
    _id char(40),
    start_date char(10),
    end_date char(10),
    monday char(1),
    tuesday char(1),
    wednesday char(1),
    thursday char(1),
    friday char(1),
    saturday char(1),
    sunday char(1)
);
CREATE TABLE routes (
    route_long_name char(200),
    route_type char(40),
    route_text_color char(40),
    agency_id char(40),
    _id char(40) PRIMARY KEY,
    route_color char(40),
    route_short_name char(40)
);
CREATE TABLE stops (
    stop_lat Decimal(9,6),
    zone_id char(30),
    stop_lon Decimal(9,6),
    _id char(30) PRIMARY KEY,
    stop_desc char(30),
    stop_name char(30),
    location_type char(30),
    stop_code char(30)
);
CREATE TABLE stop_times ( 
    trip_id char(40),
    arrival_time char(40), 
    departure_time char(40), 
    stop_id char(40), 
    stop_sequence char(40), 
    stop_headsign char(40), 
    pickup_type char(40), 
    drop_off_type char(40), 
    shape_dist_traveled char(40),
    timepoint char(20),
    FOREIGN KEY(stop_id) references stops(_id),
    FOREIGN KEY(trip_id) references trips(_id)
);
CREATE TABLE android_metadata (
    locale char(40)
);

构建数据库的方法（在StackOverflow上很常见）似乎正在工作，不确定是否正确。没有错误或通知数据库不存在。这是方法：

public void copydatabase() throws IOException {

        // Open your local db as the input stream
        InputStream myinput = mycontext.getAssets().open(DB_NAME);

        // Path to the created empty db
        String outfilename = DB_PATH + DB_NAME;

        // Open the empty db as the output stream
        OutputStream myoutput = new FileOutputStream(outfilename);

        // transfer byte from inputfile to outputfile
        byte[] buffer = new byte[1024];
        int length;
        while ((length = myinput.read(buffer)) > 0) {
            myoutput.write(buffer, 0, length);
        }

        // Close the streams
        myoutput.flush();
        myoutput.close();
        myinput.close();

    }

这是方法（在我的Database Helper文件中扩展了SQLiteOpenHelper）我用来获取停止名称的列表。稍后用于填充ViewList。

public Cursor getAllStops() {

        final String TABLE = "stops";
        final String[] COLUMN = new String[] {"stop_name as _id"};
        final String ORDER_BY = "stop_lon";
        String mypath = DB_PATH + DB_NAME;

        try {
            myDataBase = SQLiteDatabase.openDatabase(mypath, null,
                    SQLiteDatabase.OPEN_READONLY);
            Cursor c = myDataBase.query(TABLE, COLUMN, null, null, null, null, ORDER_BY, null);
//            Cursor c = myDataBase.rawQuery("select stop_name as _id from stops", null);
            if (c != null) {
                c.moveToFirst();
                return c;
            } else {
                System.out.println("unable to execute getAllStops, cursor = null!");
            }
        }
        finally {
            myDataBase.close();
        }
        return null;
    }

有没有办法检查模拟器使用的数据库。我找不到：

data/data/com.bkane56.practice.practiceapp/databases/metrolink.sqlite

非常感谢任何帮助。

更新：

错误似乎来自populateStopsDB方法：

private void populateStopsDb() {

        Cursor cursor = myHelper.getAllStops();
        String[] stops = new String[] {"_id"};
        int[] tvIds = new int[] {R.layout.listview_stops};
        SimpleCursorAdapter myCursorAdapter;
        myCursorAdapter = new SimpleCursorAdapter(getBaseContext(),R.layout.simplerow,
                cursor, stops, tvIds,0);
        lvMetroStop = (ListView) findViewById(R.id.metroStopList);
    }

抱歉原本没有发布。

由于

android sqlite数据库错误_id使用现有数据库不存在

0 个答案: