sharing a dataset

dantin

hi to all, I'm quiet new to c# and I'm looking for the best way to share a dataset between two applications in the same machine. I have to build two applications, the first one should connect to DB and fill the dataset, the second one should access the dataset created by the first application and do some job with data. How can I make the dataset readable from the second application? The dataset should be quiet big and I have to access it in a real-time application, so I'm looking for the fastest way. My idea is doing that using remoting, I will create a remote class in the first application that manages the database, and access it from the second application (for example through a remote property)...... what do you thinck about that? Thancks in advance

6 Replies

Know the answer? Post it — somebody with the same question will find it here.

mrocky21y ago
I ran into this a few years ago. A solution I build for a salvage pool company a few years ago, has a main web server maintains a copy of their complete inventory and they have a server in the office that had the official inventory database. Client apps would utilize the local server for all thier work while insurance companies, buyers and also the salvage pool company, could acess all the data through the web site with a web interface. In addition to the database that had to stay in sync between the local server and the web server, each entry had photos that were stored in directories (not in the database) that had to be in sync. This required me to create app on the server which would monitor changes and keep them in sync for both the database and images. At first it appeared that I would just use web services and push a dataset for the data (and DIME for images), but I could not seem to move "state" of the updated records. I ended up separating the changed, added and deleted records and the three datasets. There may have been an easier way, but I did not find it.
0
dingussquatbird21y ago
Hi, I was wondering if you guys found a good way to bind to a remoted DataSet. I was able to bind to a remoted DataSet, but it seemed to bind to a snapshot of the DataSet- any updates to the data were not passed back to the remoting server, and if I updated the DataSet on the remoting server side, the client objects that were bound to the DataSet did not update when the data changed. If there is a good way to do this, please let me know... I've been going crazy for about a week trying to get it working/trying to come up with a good workaround. Thanks
0
p.jones22y ago
Probably. I just achieved copy from server to client, it does appear that datarelations are copied as well as datatables even though VS Help suggested only dataset and datatable would be copied. I tried passing reference to datagrid from client to server then getting server to attempt a databind, but that gives an error that there is not a channel back to client. So I used a server side method that returns a dataset to client and that is working, now I am looking at what is visible in the client having bound my DataGrid to the DataSet. Starting to look at updates of local copy of dataset versus updates of remote original dataset, and I will bet that will require that remote object has a method to pass into it by value the dataset from the client and then merge that with original dataset. Try that tomorrow I think. There is no reason why flags settings shouldn't be retained, but we will see experimentally (tomorrow I think).
0
mrocky22y ago
Does the DataSet retain the flag for which rows where modified (added, removed, changed) after serialization?
0
p.jones22y ago
I'm working on same thing right now. You will see that DataSet is serializable and is MarshalByValue, meaning that the design aim was that you pass the actual dataset from first to second application, second application works on it, then throws it back to first application. In fact, for second throw, second program extracts a new dataset of modified/created/deleted datarows and throws that back to first program. First program then does a dataset merge of the smaller dataset comin back in with the original dataset. You are going to wrap a serialiable MarshalByvalue object within a .NET object that is what, MarshalByRef? Then you hope that Dataset doesn't have to get thrown between programs? But that will probably create performance problems if it does end with dataset not being copied to second program, since every method call on the dataset will involve a round trip through IP. I think you want to use the dataset the way that Microsft says you should (pass by value) but you want to use .NET remoting to achieve the pass, by having a server with a object deriving from MarshalByRef, and where the methods of the object take dataset object as parameter or return. I don't know yet, I'm trying next week myself. Good luck! Oh remember, datarelations apparently don't migrate, just dataset and datatable.
0
dantin22y ago
another idea could be using "in cache" memorization, but to do that I should make the two applications run in the same application domain, how can I do that?
0