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Implementing Comments and Likes in database
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Entity-relationship term for this is "category" (see the ERwin Methods Guide, section: "Subtype Relationships"). The category symbol is:
Assuming a user can like multiple entities, a same tag can be used for more than one entity but a comment is entity-specific, your model could look like this:...
Get user profile picture by Id
...t users - actually , the possible public data available - such as name and id.
I also know that a profile picture is a part of the public data, and I wondered how I'll be able to get a direct link to a profile picture of a user only by using his id?
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How to use NSJSONSerialization
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Your root json object is not a dictionary but an array:
[{"id": "1", "name":"Aaa"}, {"id": "2", "name":"Bbb"}]
This might give you a clear picture of how to handle it:
NSError *e = nil;
NSArray *jsonArray = [NSJSONSerialization JSONObjectWithData: data options: NSJSONReadingMutabl...
Are there conventions on how to name resources?
Are there conventions how to name resources in Android? For example, buttons, textViews, menus, etc.
15 Answers
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How to detect if a stored procedure already exists
... After that, you can ALTER the stored procedure to your liking.
IF object_id('YourSp') IS NULL
EXEC ('create procedure dbo.YourSp as select 1')
GO
ALTER PROCEDURE dbo.YourSp
AS
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This way, security settings, comments and other meta deta will survive the deployment.
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Sqlite primary key on multiple columns
...ent, it is an error." Yes, the railroad diagrams might indicate that is valid as well, but the text below clarifies that it is not.
– Brian Campbell
Mar 23 '11 at 19:03
11
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How to concatenate strings of a string field in a PostgreSQL 'group by' query?
... asked for, even letting you specify the delimiter string:
SELECT company_id, string_agg(employee, ', ')
FROM mytable
GROUP BY company_id;
Postgres 9.0 also added the ability to specify an ORDER BY clause in any aggregate expression; otherwise, the order is undefined. So you can now write:
SELEC...
Remove array element based on object property
... if the array is a tree structure ar beforeDeleteOperationArray=[ { "id": 3.1, "name": "test 3.1", "activityDetails": [ { "id": 22, "name": "test 3.1" }, { "id": 23, "name": "changed test 23" } ] } ] and I want to delete id...
What is the most efficient way to store tags in a database?
...ome the many-to-many obstacle.
Something like:
Table: Items
Columns: Item_ID, Item_Title, Content
Table: Tags
Columns: Tag_ID, Tag_Title
Table: Items_Tags
Columns: Item_ID, Tag_ID
It might be that your web app is very very popular and need de-normalizing down the road, but it's pointless muddy...
Cast an instance of a class to a @protocol in Objective-C
...c is a UIViewController object that conforms to MyProtocol", whereas using id <MyProtocol> translates to "vc is an object of an unknown class that conforms to MyProtocol".
This way the compiler will give you proper type checking on vc - the compiler will only give you a warning if any method ...