Is it okay to update primary key field to shift a record to the top?

should help you out In ActiveRecord how can we update a record without worrying/knowing primary key.

a = Address.find_by_cid(15)
a.user_name = 'Samuel'
a.save

fixed the issue. Will look into that further This question bears 2 different aspects.
The goal: what you want to achieve is to update a given row. Any means allowing you to reach this point is good; in other terms, if the unique key, the primary key or any other combinaison of columns not listed under any unicity constraint would be ok then you might use it. The performances: as any other query you really want to go fast and straight to the point. What does it mean? It means that you have to chose the most efficient filter in you where clause. You can measure this by:

I wish this help you For each record in table A I want to update the foreign key value of one of the fields based on new inserted record's scope_identity in table B. , You can use a cursor to loop through TableA and create the records:

DECLARE @Id int
DECLARE @ForeignKey int

DECLARE C CURSOR FOR SELECT Id FROM TableA

OPEN C

FETCH NEXT FROM C INTO @Id

WHILE @@FETCH_STATUS = 0
BEGIN
    INSERT INTO TableB VALUES (value1)
    SET @ForeignKey = SCOPE_IDENTITY()

    UPDATE TableA
    SET ForeignKey = @ForeignKey
    WHERE Id = @Id

    FETCH NEXT FROM C INTO @Id
END

CLOSE C
DEALLOCATE C

I hope this helps you . How can I use update_all for the following purpose: , In Rails4, you can do

Model.where(id: 1).update_all("field = field2 * 2")

Model.update_all("field = field2 * 2", {:id => 1})

will be helpful for those in need I've created a REST API. According to my design, we have to store user's blood sugar level per daily basis. ,
Is there any way to achieve this (or similar) result with REST?

GET /users/1/blood-sugar/

200 OK

{
    "measureDate": "2019-05-03",
    "bloodSugarLevel": 90
}

PUT /users/1/blood-sugar/
{
    "measureDate": "2019-05-04",
    "bloodSugarLevel": 86
}

204 No Content

PUT /users/1/blood-sugar/
{
    "measureDate": "2019-05-04",
    "bloodSugarLevel": 105
}