android - 如何将条目插入到 SQLite 数据库中

Question

我正在尝试从我的 View 中获取一些数据并在我的 Android 应用程序中进入我的 SQLite 数据库。

    SQLiteDatabase db = openOrCreateDatabase("SemesterDB", MODE_PRIVATE, null);
    db.execSQL("CREATE TABLE IF NOT EXISTS Semesters (Session VARCHAR, YearStart INT," +
            " MonthStart INT, DayStart INT,YearEnd INT, MonthEnd INT, DayEnd INT )");

    //extract session from view
    Spinner sessionSpinner = (Spinner) findViewById(R.id.sessionSpinner);
    String session = (String) sessionSpinner.getSelectedItem();

    //extract start date from view
    DatePicker startDatePicker = (DatePicker) findViewById(R.id.semesterStartDate);
    int startDay = startDatePicker.getDayOfMonth();
    int startMonth = startDatePicker.getMonth();
    int startYear = startDatePicker.getYear();

    //extract end date from view
DatePicker endDatePicker = (DatePicker) findViewById(R.id.semesterEndDate);
    int endDay = startDatePicker.getDayOfMonth();
    int endMonth = startDatePicker.getMonth();
    int endYear = startDatePicker.getYear();

    String sessionName = (String) session+" "+startYear;

    db.execSQL("INSERT INTO Semesters VALUES(sessionName,startYear,startMonth,startDay,endYear,endMonth,endDay);");
    db.close(); 

--所以当我将值硬编码到 db.execSQL("INSERT..... 行时，它工作得很好但是当我尝试插入具有存储值的变量时，它没有。有什么想法吗？

这是用 eclipse juno 编写的 android 2.3 应用程序。

Answer 1

您的 db.execSQL 查询也可以对其进行一些修改。

    db.execSQL("INSERT INTO Semesters VALUES(" +
    sessionName + "," +
    startYear + "," +
    startMonth + "," +
    startDay + "," +
    endYear + "," +
    endMonth + ","
    endDay + ");");

你做错了什么是在双引号中传递诸如 startYear 等变量，这些变量被视为字符串而不是它的值。所以你最终生成和执行的查询字符串结果是

INSERT INTO Semesters VALUES(sessionName,startYear,startMonth,startDay,endYear,endMonth,endDay);

因此它失败了，因为这不是有效的查询。