java - Android将变量添加到数据库查询

Question

我有这段代码不起作用。谁能告诉我我做错了什么？

    String option = names.getText().toString();

    Cursor c = db.rawQuery("SELECT * from numbers Where fname=option", null);

Answer 1

更改如下：

 Cursor c = db.rawQuery("SELECT * from numbers Where fname='"+option+"' ", null);

Answer 2

尝试这个

String query = "SELECT * from numbers Where fname='"+ option +"'";      
    database.execSQL(query);

Answer 3

更喜欢使用带有?占位符的 Prepared Statement。

String option = names.getText().toString();
String query = "SELECT * from numbers Where fname = ?"

Cursor c = db.rawQuery(query, new String[] {option});