Question

我不确定我的问题。当查询第二个表时，我没有得到这样的表..这些都在onCreate方法

中

db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" + KEY_CBID
                   + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_NAME
                   + " TEXT NOT NULL, " + KEY_RACE + " TEXT NOT NULL,"
                   + KEY_CLASS + " TEXT NOT NULL," + KEY_DEITY
                   + " TEXT NOT NULL," + KEY_GENDER + " TEXT NOT NULL,"
                   + KEY_HEIGHT + " TEXT NOT NULL," + KEY_WEIGHT
                   + " TEXT NOT NULL);");

        db.execSQL("CREATE TABLE " + DATABASE_TABLE2 + " (" + KEY_CSID
                   + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_SKILL
                   + " TEXT NOT NULL, " + KEY_CBID + " INTEGER PRIMARY KEY FOREIGN KEY);"
                   );

编辑：显示cvs

String skill = "blah test";
    Cursor c = ourDatabase.rawQuery("SELECT " + KEY_CBID + " FROM " + DATABASE_TABLE + " order by " + KEY_CBID + " DESC limit 1", null);
    if (c != null)
    {
        c.moveToFirst();
        cbid = c.getInt(0);
    }

    ContentValues cv = new ContentValues();
    cv.put(KEY_SKILL, skill);
    cv.put(KEY_CBID, cbid);
    return ourDatabase.insert(DATABASE_TABLE2, null, cv);

我的选择陈述是：

Cursor c = ourDatabase.rawQuery("SELECT " + KEY_SKILL + ", " + KEY_NAME + ", " + KEY_CBID + " FROM " + DATABASE_TABLE + ", " + DATABASE_TABLE2 + " WHERE " + DATABASE_TABLE +"."+KEY_CBID+" = " +DATABASE_TABLE2+"."+KEY_CBID+" && " +DATABASE_TABLE+"."+KEY_NAME+" = '"+item+"'", null);

Answer 1

我不相信您的第二个表正在创建，以下是如何使用外键声明表：

CREATE TABLE artist(
  artistid    INTEGER PRIMARY KEY, 
  artistname  TEXT
);

CREATE TABLE track(
  trackid     INTEGER, 
  trackname   TEXT, 
  trackartist INTEGER,
  FOREIGN KEY(trackartist) REFERENCES artist(artistid)
);

我从SQLite.org获取了这些内容。

在SQLite中默认禁用外键，Android用途：

db.execSQL("PRAGMA FOREIGN_KEYS=ON;");

在插入数据之前，如果你还没有;

Answer 2

检查您是否记录cat以查看创建第二个表时是否有错误。如果sqllite出现错误，则会记录在logcat

将新表添加到DB时，请确保已升级DB 如果您正在调用db.open，则从您的代码中获取IF，如果数据库已经创建，则它将被打开。因此，在这种情况下，不会命中创建新表的代码。因此，您必须确保升级数据库，以便删除所有现有表并重新创建

@覆盖 public void onCreate（SQLiteDatabase db）{

    createAllTables(db);
    Log.v(DBTAG, "DATABASE CREATED");
    // Toast.makeText(mCtx, "created", Toast.LENGTH_SHORT).show();
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    Log.w(DBTAG, "Upgrading database from version " + oldVersion
            + " to " + newVersion + ", which will destroy all old data");
    dropExistingTables(db);
    onCreate(db);
}

private void dropExistingTables(SQLiteDatabase db) {

    for (int i = 0; i < Utils.getDropTableQueries().size(); i++) {
        db.execSQL(Utils.getDropTableQueries().get(i));
    }
}

因此得出结论确保您正在创建表，并且在创建时没有错误。

sqlite表创建

2 个答案: