I have a mongodb database server.I want to get it fill up with large number of entries in a particular collection let say a collection named "user".
I want to know if there would be a script for saving large no of randomly created entries in my mongodb database from linux terminal or a Java code for the same.
I have a script that creates 10,000 entries in "user" collection:
> for(i=0;i<10000;i++){db.user.insert({username:'ashok'+i,password:'123'});}
This query creates the user names as ashok1 , ashok2 ,....
I want a script that could create random user names.
It could be better if I could get this done in grails.
Related
Our organization hundreds of Periscope daashboard that is generated from a database, named "Animal".
Now, let's suppose there is a table named "Puppy" with column name "is_spotted". Is there an easy way to find out whether "is_spotted" has been used to create a dashboard, without going through every single dashboards?
I would like to join the user object and project permission object to see how many users have been assigned to a project, for audit purpose. I don't see a common field with common values (email address or first name/last name) between these objects. I used Excel plugin to retrieve two separate data sheet and unable to map them. Any thoughts on this on how to do this?
You're probably seeing something similar to the following when you query on ProjectPermissions:
In this situation, the default User object selected from the "Columns" picker in the query dialog, gives you the User's DisplayName, which doesn't unambiguously map to a Rally UserID.
Note, however, that you can add dot-notation sub-fields of Objects manually by typing them into the Columns field. In the following example, I've included User.Username and User.LastLoginDate as additional fields I want to show on the Permissions report:
Of course, you could also just include User.Username, and run a second query on the User object with all fields selected, and do a join in Excel.
One note of caution - if you have many users (say 1,000), and a lot of projects, (say 1,000, which is not uncommon in large Rally subscriptions), querying directly against the ProjectPermissions endpoint can rapidly result in total results that number on the order of 10^6. This will probably time out in an Excel query.
The Rally User Management: User Permissions Summary script works around this by querying Permissions in a loop on a user-by-user basis. It's slow, but it returns results without timeouts. Certainly not as convenient as Excel either - you need to install Ruby 1.9.2+ and the rally_api gem to get it working.
I'm building a chatroom application, and I want to keep track of which users are currently in the chatroom. However, I can't just store this array of users (or maybe a list would be better) in a field in one of my records in the Chatroom table.
Obviously one of the SQL data types is not an array, which leads me to this issue: what is the best way to fake/mock array functionality in a SQL database?
It seems there are 3 options:
1: Store the list/array of users as a string separated by commas, and just do some parsing when I want to get it back to an array
2: Since the max amount of users is allowed to be 10, just have 10 extra fields on each Chatroom record representing the users who are currently there
3: Have a new table Userchats, which has two fields, a reference to the chatroom, and a user name
I dunno, which is the best? I'm also open to other options. I'm also using Rails, which seems irrelevant here, but may be of interest.
Option 3 is the best. This is how you do it, in a relational schema. It is also the most flexible and future-proof option.
It can grow easier in width (extra columns say, a date joined, a channel status, a timestamp last talked) and length (extra rows when you decide there now can be 15 users in a room instead of 10).
The proper way to do this is to add an extra table representing an instance of a user being in a chatroom. In most cases, this is probably what you will want to do, since it gives you more flexibility in the types of queries you can do (for instance: list all chatrooms a particular user is in, find the average number of people in each chatroom, etc.) You would just need to add a new table - something like chat_room_users, with a chat_room_id, and a user_id.
If you're deadset on not adding an extra table, then Rails (or more specifically ActiveRecord), does have some functionality to store data structures like arrays in a SQL column. Just set up your column as a string or text type in a Rails migration, and add:
serialize :users
You can then use this column as a normal Ruby array / object, and ActiveRecord will automatically serialize / deserialize this object as you work with it. Keep in mind that's there are a lot of tradeoffs with this approach - you will never be able to query what users are in a particular room using SQL and will instead need to pull all data down to Ruby before working with it.
I need some guidance on adding / updating SQL records using EF. Lets say I am writing an application that stores info about files on a hard disk, into an EF4 database. When you press a button, it will scan all the files in a specified path (maybe the whole drive), and store information in the database like the file size, change date etc. Sometimes the file will already be recorded from a previous run, so its properties should be updated; sometimes a batch of files will be detected for the first time and will need to be added.
I am using EF4, and I am seeking the most efficient way of adding new file information and updating existing records. As I understand it, when I press the search button and files are detected, I will have to check for the presence of a file entity, retrieve its ID field, and use that to add or update related information; but if it does not exist already, I will need to create a tree that represents it and its related objects (eg. its folder path), and add that. I will also have to handle the merging of the folder path object as well.
It occurs to me that if there are many millions of files, as there might be on a server, loading the whole database into the context is not ideal or practical. So for every file, I might conceivably have to make a round trip to the database on disk to detect if the entry exists already, retrieve its ID if it exists, then another trip to update. Is there a more efficient way I can insert/update multiple file object trees in one trip to the DB? If there was an Entity context method like 'Insert If It Doesnt Exist And Update If It Does' for example, then I could wrap up multiple in a transaction?
I imagine this would be a fairly common requirement, how is it best done in EF? Any thoughts would be appreciated.(oh my DB is SQLITE if that makes a difference)
You can check if the record already exists in the DB. If not, create and add the record. You can then set the fields of the record which will be common to insert and update like the sample code below.
var strategy_property_in_db = _dbContext.ParameterValues().Where(r => r.Name == strategy_property.Name).FirstOrDefault();
if (strategy_property_in_db == null)
{
strategy_property_in_db = new ParameterValue() { Name = strategy_property.Name };
_dbContext.AddObject("ParameterValues", strategy_property_in_db);
}
strategy_property_in_db.Value = strategy_property.Value;
At the moment the team i am working with is looking into the possibility of storing data which is entered by users from a series of input wizard screens as an XML blob in the database. the main reason for this being that i would like to write the input wizard as a component which can be brought into a number of systems without having to bring with it a large table structure.
To try to clarify if the wizard has 100 input fields (for example) then if i go with the normal relational db structure then their will be a 1 to 1 relationship so will have 100 columns in database. So to get this working in another system will have to bring the tables,strore procedures etc into the new system.
I have a number of reservations about this but i would like peoples opinions??
thanks
If those inputted fields don't need to be updated or to be used for later calculation or computation some values using xml or JSON is a smart choice.
so for your scenario seems like its a perfect solution