Android SQLite 注意點（問題解決）

Android SQLite 注意點（問題解決）

注意：

一. sql語句

 String sql = "insert into " + TABLE_NAME
                + " ("
                + ID + ","
                + NAME + ","
                + TAG + ","
                + STATUS + ","
                + IMGPATH + ","
                + IMG
                + ")"
                + " values ("
                + getCursor().getCount() + ",\'"
                + name + "\',\'"
                + tag + "\',\'"
                + status + "\',\'"
                + imgPath + "\',\'"
                + img
                + "\')";

注意：這樣寫的sql語句 參數兩邊要加’ 例：‘參數’。轉義 \’

二.Cursor（遊標）的理解

 private List list = new ArrayList();
    public List<String> queryAllTag() {
        Cursor cursor = getCursor();
        if (cursor != null && cursor.moveToFirst()) {
            if (cursor.getCount() > 0) {
                    add(cursor);
                while (cursor.moveToNext()) {
                    add(cursor);
                }
            }

        }
        return list;
    }
private void add(Cursor cursor){
    String s = cursor.getString(cursor.getColumnIndex("Tag"));
    list.add(s);
}

注意：cursor.moveToFirst() 了之後就有第一條數據了，cursor.moveToNext() 換下一行。所以在 cursor.moveToFirst() 後記得有條數據（第一條）。