Android將變量添加到數據庫查詢

Question

我有這段代碼不起作用。誰能告訴我我做錯了什麼？如下

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

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

Answer 1

變化：

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

Answer 2

試試這個

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

Answer 3

更喜歡使用預處理語句與?佔位符。

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

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