[VB.NET] Databases

Conrad11 · 26 Oct 2006 at 20:12

Hi there,

Does anyone have any good tutorials for learning about data connections and querying databases, etc?

I like the video style tutorials there sometimes is if anyone has any of those.

Thanks.

TrUz · 26 Oct 2006 at 21:25

How do you want to go about accessing your database? By pure code or using DataSet's etc...? Are you going to be binding any controls?

There is loads of tutorials on the net, do a search on google for 'VB OleDb' or something similar.

TrUz

Conrad11 · 26 Oct 2006 at 21:30

Basically, i want to go about it in the easiest way.

I dont think i will be doing any binding. I think i will have to code the results into controls, cause i want to use things like tree views controls etc.

Thanks.

akakjs · 26 Oct 2006 at 22:03

Conrad11 said:
Basically, i want to go about it in the easiest way.

I dont think i will be doing any binding. I think i will have to code the results into controls, cause i want to use things like tree views controls etc.

Thanks.

You'll be binding then

This is the best explaination of databinding I've found Hope it helps

akakjs

Conrad11 · 26 Oct 2006 at 22:53

I cant seem to get the treeview control to work using binding, surely you have to do it manually to add all the nodes etc....?

TrUz · 26 Oct 2006 at 23:35

TreeView is not a data bound control. Well you can data bind the Tag and that is it. You will need to manually code your TreeView.

TrUz

Conrad11 · 26 Oct 2006 at 23:36

TrUz said:
TreeView is not a data bound control. Well you can data bind the Tag and that is it. You will need to manually code your TreeView.

TrUz

Thanks, what i thought, got a bit confused with that the guy said above.

Conrad11 · 29 Oct 2006 at 00:47

I did manage to get the treeview thing to work using ADO.NET.

But i have another question to do with effiency and making my program query quicker, because my program is data driven.

The database in Ms Access btw.

There is only one table which has anything changed which is the users table.

The other three tables are only read from.

There is a big table which makes the bulk of the database and i want to make querying from this as efficient as i can as this table will have roughtly 100K records each 1KB.

What shoud and how should i be reading the data. Put it in datatabbles, sets, readers? (I am new to ADO.NET and havent a clue).

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The users table needs to be able to access over the network, whereas the other tables can be local. Should i split it into two different databases and have the users database on the network and the other local?

====

I also wanted to know when was the appropriate times to open and close the connections, currently i am not doing that at all, do you have to open and close the connections?

Thanks for any input/advice.

Goksly · 29 Oct 2006 at 15:51

There is a big table which makes the bulk of the database and i want to make querying from this as efficient as i can as this table will have roughtly 100K records each 1KB.

Try splitting (normalising) the table down. This will make the database more logical, easier to maintain and should speed it up (as the database will be looking at less information - unless you are always bringing back the whole row).

What shoud and how should i be reading the data. Put it in datatabbles, sets, readers? (I am new to ADO.NET and havent a clue).

If you are just going to read the data, use a data reader (very fast.... but any changes made will not go through to the database). If you want to update the database, then use a data adaptor.
As for handling the data once its down, its best to use the logical objects. If you are holding many tables, then use a dataset, however if the data being displayed is just from one table, use a data table.

The users table needs to be able to access over the network, whereas the other tables can be local. Should i split it into two different databases and have the users database on the network and the other local?

Always keep related data together.

I also wanted to know when was the appropriate times to open and close the connections, currently i am not doing that at all, do you have to open and close the connections?

If you are just reading the data, then open it, read the data, and close it as soon as you can. This is especially important for access which doesnt like too many connections to be open to it at once. For data adaptors im not 100% sure of the situation - maybe someone else can help

Hope that helps

Conrad11 · 29 Oct 2006 at 16:37

Hope that helps

Very helpful, thanks for taking the time to reply.

Always keep related data together.

The only way the user data is related to the other data is the fact that they are in the same program, or is that what you meant

Try splitting (normalising) the table down. This will make the database more logical, easier to maintain and should speed it up (as the database will be looking at less information - unless you are always bringing back the whole row).

I am not always taking the whole row, so should i shorten it so it only has the data that is retrieved and have the other information in another table with an id connected to it?

If you are just reading the data, then open it, read the data, and close it as soon as you can. This is especially important for access which doesnt like too many connections to be open to it at once. For data adaptors im not 100% sure of the situation - maybe someone else can help

Ah ok thanks, i am using data adapters at the moment and i'm not opening or closing the connection at all and it works? Is that correct or am i using it incorrectly and its by chance that it works?

Thanks again!!