保存在SQLite数据库的ArrayList [英] Saving ArrayLists in SQLite databases
问题描述
所以,我要救double值的有序集合,我希望能够插入,检索或轻松地删除这个任意值。作为这样的,我使用的是一个ArrayList,在那里我定义了一类称为双打存储的双重价值。
So I want to save an ordered set of double values, and I want to be able to insert, retrieve or delete any value from this easily. As of such, I'm using a an ArrayList, where I define a class called Doubles to store the double values.
我如何保存此ArrayList中的一个记录在SQLite数据库?我的意思是...我应该列类型?能不能做到?
How do I store this arraylist in a record in an SQLite database? I mean...what should the columns type be? Can it be done?
感谢。
推荐答案
您不能插入ArrayList中直接进入sqlite的。相反,你可以使用的JSONObject(org.json.JSONObject)插入ArrayList中。请检查下面的代码片段,您可以尝试像下面......
You cannot insert ArrayList directly into Sqlite. Instead, you could use JSONObject (org.json.JSONObject) to insert the ArrayList. Please check below snippet, you can try something like below....
要插入,
JSONObject json = new JSONObject();
json.put("uniqueArrays", new JSONArray(items));
String arrayList = json.toString();
将字符串到数据库。
Insert the string into db.
要读, 阅读从数据库字符串作为字符串,
To Read, Read the string from db as String,
JSONObject json = new JSONObject(stringreadfromsqlite);
ArrayList items = json.optJSONArray("uniqueArrays");
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