在android中创建一个多表SQL数据库

概述我正在尝试为我的 Android应用程序创建一个多表数据库.我正在按照 http://androidforbeginners.blogspot.com/2010/01/creating-multiple-sqlite-database.html这个网站上的建议来做这件事.我继续得到以下错误.该错误似乎是由数据库表的onCreate引起的. 如果你在DBHelper类中查看我的onCreate,我有 我正在尝试为我的 Android应用程序创建一个多表数据库.我正在按照 http://androidforbeginners.blogspot.com/2010/01/creating-multiple-sqlite-database.html这个网站上的建议来做这件事.我继续得到以下错误.该错误似乎是由数据库表的onCreate引起的.

如果你在DBHelper类中查看我的onCreate,我有两个注释掉了.这使得它无论哪一个都不公开都可以工作.

必须有一种方法来创建多表数据库,因为数据库中的单个表几乎违背了拥有数据库的目的.

10-23 02:11:35.383: ERROR/AndroIDRuntime(300): Caused by: androID.database.sqlite.sqliteException: Can't upgrade read-only database from version 0 to 1: /data/data/com.parkingticket/databases/Tickets.db

提前致谢.

这是我的代码

package com.parkingticket;   import java.sql.sqlException;   import androID.content.ContentValues;   import androID.content.Context;   import androID.database.Cursor;   import androID.database.sqlite.sqliteDatabase;   import androID.database.sqlite.sqliteDatabase.CursorFactory;   import androID.database.sqlite.sqliteException;   import androID.database.sqlite.sqliteOpenHelper;   import androID.util.Log;   public class TicketDBAdapter    {private static final String DATABASE_name="Tickets.db";private static final int DATABASE_VERSION = 1;private static final String PARKEDCARS_table = "ParkedCars";private static final String PARKINGMETERS_table = "ParkingMeters";private static final String PARKINGTICKETS_table = "ParkingTickets";private static final String POliCEOFFICERS_table = "PoliceOfficers";// The name and column index for each column in PARKEDCARSpublic static final String KEY_CARID = "carID";    public static final int CARID_ColUMN = 0;public static final String KEY_CARMAKE = "Make";    public static final int CARMAKE_ColUMN = 1;public static final String KEY_CARMODEL = "Model";    public static final int CARMODEL_ColUMN = 2;public static final String KEY_CARcolor = "color";    public static final int CARcolor_ColUMN = 3;public static final String KEY_CARliCENSENUMBER = "licenseNumber";    public static final int CARliCENSENUMBER_ColUMN = 4;public static final String KEY_CARMINUTESPARKED = "MinutesParked";    public static final int CARMINUTESPARKED_ColUMN = 5;// The name and column index for each column in PARKINGMETERSpublic static final String KEY_METERID = "meterID";    public static final int METERID_ColUMN = 0;public static final String KEY_MINUTESPURCHASED = "MinutesPurchased";    public static final int MINUTESPURCHASED_ColUMN = 1;// The name and column index for each column in PARKINGTICKETS    //Todo create the columns and indexs for parking tickets// The name and column index for each column in POliCEOFFICERSpublic static final String KEY_OFFICERID = "officerID";    public static final int OFFICERID_ColUMN = 0;public static final String KEY_OFFICERname = "name";    public static final int OFFICERname_ColUMN = 1;public static final String KEY_OFFICERBADGE = "BadgeNumber";    public static final int OFFICERBADE_ColUMN = 2;//Variable to hold the database instanceprivate sqliteDatabase ticketDB;//Context of the application using the database.private final Context context;//Database open/upgrade helperprivate TicketDBHelper ticketDBHelper;public TicketDBAdapter(Context _context){    context = _context;    ticketDBHelper = new TicketDBHelper(context,DATABASE_name,null,DATABASE_VERSION);}public voID open() throws sqliteException{    try    {        ticketDB = ticketDBHelper.getWritableDatabase();    }    catch(sqliteException ex)    {        ticketDB = ticketDBHelper.getReadableDatabase();    }}public voID close(){    ticketDB.close();} //Insert a new ParkedCarpublic long insertParkedCar(ParkedCar _car){    //Create a new row of values to insert    ContentValues newParkedCarValues = new ContentValues();    //Assign values for each row    newParkedCarValues.put(KEY_CARMAKE,_car.getMake());    newParkedCarValues.put(KEY_CARMODEL,_car.getModel());    newParkedCarValues.put(KEY_CARcolor,_car.getcolor());    newParkedCarValues.put(KEY_CARliCENSENUMBER,_car.getlicenseNumber());    newParkedCarValues.put(KEY_CARMINUTESPARKED,_car.getMinutesParked());    //Insert the row    return ticketDB.insert(PARKEDCARS_table,newParkedCarValues);}//Remove a ParkedCar based on its indexpublic boolean removeParkedCar(long _rowIndex){    return ticketDB.delete(PARKEDCARS_table,KEY_CARID + "=" + _rowIndex,null)>0;}//Update a ParkedCar's MinutesParked//Todo Create an update for ParkedCar's minutesParked.public Cursor getAllParkedCarsCursor(){    return ticketDB.query(PARKEDCARS_table,new String[] {KEY_CARID,KEY_CARMAKE,KEY_CARMODEL,KEY_CARcolor,KEY_CARliCENSENUMBER,KEY_CARMINUTESPARKED},null);}public Cursor setCursorParkedCar(long _rowIndex) throws sqlException{    Cursor result = ticketDB.query(true,PARKEDCARS_table,new String []{KEY_CARID},null);    if ((result.getCount() == 0) || !result.movetoFirst())    {        throw new sqlException("No ParkedCar found for row: " + _rowIndex);    }    return result;}public static class TicketDBHelper extends sqliteOpenHelper{    public TicketDBHelper(Context context,String name,CursorFactory factory,int version)    {        super(context,name,factory,version);    }    //sql Statement to create PARKEDCARS table    private static final String PARKEDCARS_CREATE = "create table " + PARKEDCARS_table + " (" + KEY_CARID + " integer primary key autoincrement," + KEY_CARMAKE + " text not null," + KEY_CARMODEL + " text not null," + KEY_CARcolor + " text not null," + KEY_CARliCENSENUMBER + " text not null," + KEY_CARMINUTESPARKED + "int not null);";    //sql Statement to create ParkingMeters table    private static final String PARKINGMETERS_CREATE = "create table" + PARKINGMETERS_table + " (" + KEY_METERID + " integer primary key autoincrement," + KEY_MINUTESPURCHASED + " int not null);";    //sql Statement to create ParkingTickets table    //Todo create the statement for parkingTickets    //sql Statement to create PoliceOfficers table    private static final String POliCEOFFICERS_CREATE = "create table" + POliCEOFFICERS_table + " (" + KEY_OFFICERID + " integer primary key autoincrement," + KEY_OFFICERname + " text not null," + KEY_OFFICERBADGE + "text not null);";    //Called when no database exists in disk and the helper class needs to create a new one.    @OverrIDe    public voID onCreate(sqliteDatabase _db)    {                //_db.execsql(PARKEDCARS_CREATE);          _db.execsql(PARKINGMETERS_CREATE);                 //_db.execsql(POliCEOFFICERS_CREATE);    }    //Called when there is a database verion mismatch meaning that the version of the database on disk needs to be upgraded to the current version    @OverrIDe    public voID onUpgrade(sqliteDatabase _db,int _oldVersion,int _newVersion)    {        //Log the version upgrade.        Log.w("TaskDBAdapter","Upgrading from version " + _oldVersion + " to " + _newVersion + ",which will destroy all old data");        //Upgrade the existing database to conform to the new version        //Multiple prevIoUs versions can be handled by comparing _oldVersoin and _newVersion values        //The simplest case is to drop teh old table and create a new one.        _db.execsql("DROP table IF EXISTS " + PARKEDCARS_table);        _db.execsql("DROP table IF EXISTS " + PARKINGMETERS_table);        _db.execsql("DROP table IF EXISTS " + POliCEOFFICERS_table);        onCreate(_db);    }}  }

解决方法 我知道我迟到了,但我认为这可能有助于其他人阅读这篇文章.
我有同样的问题,它是关于空格的,当你在编写关于空间的SQL查询时要非常小心.例如在上面的代码中,你可以注意到最后没有空格：

 KEY_OFFICERBADGE“text not null”

所以基本上,你已经声明了一个没有类型的列.希望它有所帮助.

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