Question

我想在SQLite中创建2个（以及更多）表，但是存在问题。我之前创建了一个表并且它正在工作但是现在当我尝试制作第二个表并插入一些数据时，它说“没有这样的表”

为什么这不起作用？

@Override
    public void onCreate(SQLiteDatabase db) {


        // create wedstrijden table
        String CREATE_WEDSTRIJD_TABLE = "CREATE TABLE wedstrijd ( " +
                "id                 INTEGER PRIMARY KEY, " + 
                "datum              TEXT, " +
                "thuisclub          NUMERIC, " +
                "bezoekers          NUMERIC, " +
                "thuistenue         TEXT, " +
                "bezoekerstenue     TEXT, " +
                "aftrap             TEXT, " +
                "begintijd1ehelft   TEXT, " +
                "eindtijd1ehelft    TEXT, " +
                "extratijd1ehelft   TEXT, " +
                "begintijd2ehelft   TEXT, " +
                "eindtijd2ehelft    TEXT, " +
                "extratijd2ehelft   TEXT, " +
                "verlengen          NUMERIC, " +
                "penalties          NUMERIC, " +
                "begintijdverlengen TEXT, " +
                "eindtijdverlengen  TEXT, " +
                "totalespeeltijd    TEXT, " +
                "begintijdpenalties TEXT, " +
                "eindtijdpenalties  TEXT, " +
                "doelpuntenthuis    NUMERIC, " +
                "doelpuntenuit      NUMERIC)";
        db.execSQL(CREATE_WEDSTRIJD_TABLE);

        // create teams table
        String CREATE_TEAM_TABLE = "CREATE TABLE teams ( " +
                "id      INTEGER PRIMARY KEY, " +
                "naam    TEXT, " +
                "trainer TEXT, " +
                "tenue   TEXT)";
        db.execSQL(CREATE_TEAM_TABLE);

    }

要添加数据，请执行以下操作：

db.addTeam(new DatabaseTeams(bezoekersTeam,bezoekersTrainer,bezoekersTenue));

public void addTeam(DatabaseTeams team){
// 1. get reference to writable DB
SQLiteDatabase db = this.getWritableDatabase();
// 2. create ContentValues to add key "column"/value
ContentValues values = new ContentValues();
values.put(KEY_NAAM_TEAM, team.getTeamNaamThuis()); 
values.put(KEY_TRAINER_TEAM, team.getTeamTrainerThuis()); 
values.put(KEY_TENUE_TEAM, team.getTeamTenueThuis()); 
// 3. insert
long lastId = db.insert(TABLE_TEAM, // table
null, //nullColumnHack
values); // key/value -> keys = column names/ values = column values
Log.d("Insert new team "+lastId+" invoeren", team.toString());
// 4. close
db.close(); 
}

值为：

// Team Info
    // Team table name
    private static final String TABLE_TEAM = "teams";

    // Team table Columns names
    private static final String KEY_ID_TEAM = "id";
    private static final String KEY_NAAM_TEAM = "naam";
    private static final String KEY_TRAINER_TEAM = "trainer";
    private static final String KEY_TENUE_TEAM = "tenue";

    private static final String[] COLUMNS_TEAM = {KEY_ID_TEAM,KEY_NAAM_TEAM,KEY_TRAINER_TEAM,KEY_TENUE_TEAM};

Answer 1

您的问题可能是onCreate()未被调用。

每次更改数据库结构时，都需要增加数据库版本，即SQLiteOpenHelper中的int DATABASE_VERSION。您还必须正确实现onUpgrade()，因为当Android检测到数据库版本已增加时会调用此方法。这样做：

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // drop old tables
        onCreate(db);
    }

有关更详尽的说明和代码示例，请参阅android tutorial on creating an sqlite helper。

无法在Android SQLite中创建两个表

1 个答案: