android - 如何在android中的sqlite中创建多个表？

Question

我的数据库中有三个表。我尝试了很多关于在 sqlite 中创建数据库的示例，结果发现它们中的大多数只是一个表....

我尝试了很多方法，比如执行查询 db.execSQL(query) 在 onCreate 中创建每个表，但它出错了..

SO 有什么好的策略可以创建多个表？？？我应该为每个表创建许多类代表扩展 SQLiteOpenHelper 吗？？？

谢谢

这是我的类扩展 SQLiteOpenHelper 的一部分

public void onCreate(SQLiteDatabase db) {
    // TODO Auto-generated method stub
    try{
        db.execSQL(CREATE_TABLE_1);
        db.execSQL(CREATE_TABLE_2);
        db.execSQL(CREATE_TABLE_3);
    }catch( Exception e){
        Log.e("dbAdapter", e.getMessage().toString());
    }

}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // TODO Auto-generated method stub
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_1);
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_2);
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_3);
    onCreate(db);
}

好像table2和table3没有创建 因为当我将数据插入表 2 时出现错误 - 找不到这样的表 2!!!

这里是我创建的表字符串:

//create script patient
public static String CREATE_TABLE_1= "create table " +
TABLE_USER + " (" +
USER_ID + " integer primary key autoincrement, " +
USER_NAME + " text not null, " +
DEVICE_KEY + " text not null  );" ;

public static String CREATE_TABLE_2= "create table " +
TABLE_GPS_SETTING + " (" +
SETTIN + " integer primary key autoincrement, " +
REFRESVAL + " long not null, " +
ODE + " varchar(20), " +
_TYPE + " varchar(20) );" ;

public static String CREATE_TABLE_3= "create table " +
TABLE_W + " (" +
GPD + " integer primary key autoincrement, " +
LITUDE + " double, " +
LITUDE + " double, " + 
ATUDE + "integer,"+
M + "integer,"+
DTION + "integer,"+
DANCE + "integer,"+
LDD + "integer,"+
SESID + "double,"+
ACCCY + "double,"+
TMP + "long,"+
TATE + "TEXT,"+
D_ID + "TEXT);" ;

有什么想法吗？

Answer 1

我相信有 no such thing as a varchar in SQLite .使用文本。