将列表放入 android 中的 SQLite 数据库 [英] Putting a list into a SQLite database in android

问题描述

我有一个 List，我想把它放到 SQLite 数据库中.

I have a List<Contact> and I'ld like to put it into a SQLite database.

我读过一些其他帖子，说您需要将 List 转换为 JSONArray 并将其作为 TEXT 字段存储在数组中，但我是初学者，这一切都非常令人困惑.

I've read some other posts saying you need to convert the List to a JSONArray and store it as a TEXT field in the array but I'm a beginner and this is all very confusing.

到目前为止我有一个方法如下:

So far I have a method as follows:

public JSONArray void toJSON() {
JSONArray jsonArray = new JSONArray(myList);
return jsonArray
}

然后在我的 sqlite 数据库中我说:

Then in my sqlite database I say:

ContentValues values = new ContentValues();
        values.put(KEY_CONTACTS, group.toJSON());

但我收到一个错误消息，说ContentValues 类型中的 put(String, String) 方法不适用于参数 (String, JSONArray).我不知道如何正确地把它变成一个字符串.任何帮助将不胜感激.

But I am getting an error saying The method put(String, String) in the type ContentValues is not applicable for the arguments (String, JSONArray). I dont know how to properly get it to a string though. Any help would be appreciated.

推荐答案

有一个示例代码，希望对你有帮助.

there is one sample code, hope it could help u.

class Contact {
    public int id,
    public String name;
    public String phone;
}
class ContactColumns {
    public static final String ID = "_id";
    public static final String NAME = "name";
    public static final String PHONE = "phone";
}
private List<ContentValues> buildContentValueList(String jsonStr) {
    if (TextUtils.isEmpty(jsonStr)) {
        return null;
    }
    List<ContentValues> list = new ArrayList<ContentValues>();
    JSONArray jsonArray = new JSONArray(jsonStr);
    for (i = 0; i< jsonArray.length(); i++) {
        JSONObject jb = jsonArray.optJSONObject(i);
        if (jb == null) {
            continue;
        }

        ContentValues values = new ContentValues();
        values.put(ContactColumns.ID, jb.optInt("ID_KEY"));
        values.put(ContactColumns.NAME, jb.optString("NAME_KEY"));
        values.put(ContactColumns.PHONE, jb.optString("PHONE_KEY"));
        list.add(contact);
    }
    return list;
}

public void insertContact(List<ContentValues> valueList) {
    if (valueList.size() > 0) {
        ContentValues[] valueArray = new ContentValues[valueList.size()];
        valueArray = valueList.toArray(valueArray);
        getContentResolver().bulkInsert(ContactTable.URI, valueArray);
    }
}

you can call insertContact(buildContentValueList(jsonString)) to complete, that's all.

这篇关于将列表放入 android 中的 SQLite 数据库的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！