如何在sqlite ios中向现有表添加唯一约束? [英] How to add unique constraint to existing table in sqlite ios?

问题描述

我已经通过sqlite数据库浏览器创建了一个数据库和表.我想让用户从Facebook添加选定的朋友名称，但只能添加一次.我如何在sqlite中添加约束?

I have made a database and table already through the sqlite database browser. I want let users add selected friends names from facebook but only once. How di I add constraints in sqlite ?

我检查了sqlite数据库浏览器，但是没有什么可以更改的.

I checked the sqlite database browser but there is nothing there to change it.

我尝试过使用lita，但是在lita中有使其不为null和唯一的选项，但是我无法单击该复选框.

I tried lita for it but in there is option in lita to make it non null and unique but I cant click that checkbox.

推荐答案

我假设您使用的是FireFox的SQLiteManager，请重新创建表，通常在创建表后不允许更改约束

I am assuming you are using SQLiteManager from FireFox, please create the table again, normally it doesn't allow to change the constraints when you have already created a table.

注意-也可以使用代码来完成，这是另一种方式.

NOTE - It can be done using code too, this is another way of doing it..

已编辑见下图

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