SELECT predmet FROM predmeti WHERE dan=PONEDELJEK and ura=2 and oddelek=4c

您需要引用字符串文字，例如:

You need to quote your string literals, for example:

SELECT predmet FROM predmeti WHERE dan='PONEDELJEK' and ura=2 and oddelek='4c'

但是***将?占位符用于文字:

But it's better to use ? placeholder for literals:

SELECT predmet FROM predmeti WHERE dan=? and ura=? and oddelek=?

，然后将您的null selectionArgs更改为

new String[] { dan, Integer.toString(ura), oddelek }