Visual Basic

dataRows, dataCols, etc...?

4-Aug-04 6:41

thanks, I never thought it would be done like that. I will see what I can do.

FileCopy

MJZ3-Aug-04 16:59

MJZ

3-Aug-04 16:59

Is there a simple function similar to FileCopy that allows wildcards. I want to copy multiple files rather than one file at a time.

I am using VB 6

Any assistance appreciated.

Mike Laugh | :laugh:

New to IT

Re: FileCopy

Murugavel S4-Aug-04 0:27

Murugavel S

4-Aug-04 0:27

Use System.IO.Directory and its "Move" method to move the entire contents.

If you are specific about the file types use "Getfiles" method and get them into a string array and copy them.

Cheers Wink | ;)

Re: FileCopy

Nick Seng4-Aug-04 15:16

Nick Seng

4-Aug-04 15:16

Murugavel S wrote:
Use System.IO.Directory

He's using VB6. Wink | ;)

"if you vote me down, I shall become more powerful than you can possibly imagine" - Michael P. Butler.

kowplunk3-Aug-04 16:04

3-Aug-04 16:04

I am a little confused with all of these. Right now to pull data from the db ans display it I use a dataAdaptor, dataSet, dataGris, and a dataView. Now this all works for me, but I am sure that I am only skimmig the surface. Seeing as everything works with what I use, what are dataRows, and DataCols for? Are they for creating your own columns within a pre-defined or manually created dataSet.

I am presently trying to replace a class structure simular to a Book->page->word like structue with a dataset, and use dataviews to view all the data the corresponds to the page being viewed, and I think that this might be a much better way than what I have now.

Thanks for any input.

Murugavel S4-Aug-04 0:52

Murugavel S

4-Aug-04 0:52

DataRow represents a single row of a datatable. i.e to display / insert a single row of a datatable.

DataColumn represents a single column of a datatable. A new column can be created in the datatable in otherwords to create the schema of Datatable.
You can set Constraints, Identity, Null/Not Null.

Now, datarow can be used to create a new row in a datacolumn.

Basically, think the above two as equivalent to the action that you carry out in your database server.

Cheers Wink | ;)

kowplunk4-Aug-04 6:40

4-Aug-04 6:40

I am not sure if this way of thinking is right, but...
Are creating data columns and dataRows, used more for allowing for control of what is going into the dataTable? I was thinking that maybe when using the dataAdaptor that the dataCols, etc is all down behind the scene.

Another question though.

I can't seem to figure out how to set up a data view to only show certain columns. There is a rowFilter, which is obviously like the where clause in an sql string, but right now I need to be able to only show the cols that I want. Does anyone know how to do this. The book that I found only has a half a page on the dataView so there is not much detail on this subject.

Thanks for the help

Jim Matthews4-Aug-04 7:21

4-Aug-04 7:21

datacolumns are used for defining the structure or schema of the data table. so, in a sense, yes your thinking is correct.

when using dataadapter.fill, the datatable you point to assumes the structure of the resulting data.

for data views, i don't believe you can filter columns out of a view. to do this, you would use whatever tool you're using to display the data table to the user. i.e. a datagrid or combobox etc.

if using a datagrid, define a tablestyle for your datagrid and then define a gridcolumnstyle for each column you wish to actually display. don't define one for the columns you wish to hide, or you could define the grid columnstyle for the ones you wish to hide and just set their width property to 0.

hope this helps.

- jim

kowplunk4-Aug-04 7:50

4-Aug-04 7:50

that makes sense. I made things work by creating a custom table inserting only the cols that I want then the corresponding data for those columns, BUT if I make changes to that data, is it going to affect the data in the dataSet and therefore be able to be submitted, since the custom dataTable that is created is not part of the dataSet?

Thanks again

Jim Matthews4-Aug-04 8:08

4-Aug-04 8:08

no problem.

i would advise against doing it the way you said you were able to get around your problem for two main reasons.

1. you are going to have problems updating back to the datasource. this is because you've changed the structure of the table. when you use fill from the dataadapter to populate a table the dataadapter itself holds information regarding the information that was pulled and automatically creates insert, update and delete statements based on the structure of what was initially pulled. you could certainly call myAdapter.Update(myNewTable) but it will no doubt cause problems because the structure has changed. This is of course unless you manually update the commandtext property of the corresponding commands to reflect the structure of the new table.

2. you are incurring an unnecessary performance hit by copying the data from the table that is returned by the adapter into a new table. this will be more of an issue as the amount of data returned increases.

so basically, you can do it this way, but i don't really think it's necessary in your situation. my recommendation would be to just pull the data out using the dataadapter, let the user update the data, and use the same dataadapter to update, if possible.

If using the same dataadapter isn't possible, then you have to look into how to set the properties of the dataadatper and it's underlying Insert, Update, and Delete Commands and their corresponding CommandText properties to get the data back into the database correctly.

- jim

kowplunk4-Aug-04 10:46

4-Aug-04 10:46

I kinda thought that it might be a problem. I am trying to get a dataGrid style to work, but I can't find a lot on it. This is what I have so far on the methods that links the dataSet and the dataGrid

I have created the style through the menus, creating the grid style and all column styles to hide certain columns, but I am having a hard time makig the datagrid use the style. There does not seem to be a lot written on this subject.

Jim Matthews4-Aug-04 10:51

4-Aug-04 10:51

i had a hard time when first using these as well. the more you use them the easier it gets.

i would say first, make sure that all of the mappingname properties for the tablestyle and columnstyles are spelled correctly.

tablestyle.mappingname should = datatable.tablename
columnstyle.mappingname should = datatable.cols(x).columnname (i.e. the column it should map to)

if the grid isn't using the tablestyle at all the most likely culprit would be the tablestyle mappingname property.

-jim

kowplunk4-Aug-04 11:09

4-Aug-04 11:09

ya it was the tableStyle mapping property, but I was leaving that out because I was trying to set that within the code to allow different functions to display different columns.

Is the mapping name mor for assigning different styles to different tables within the datagrid? Because I can't figure out how to do it via code.

kowplunk4-Aug-04 11:18

4-Aug-04 11:18

ok, I think I am just too tired to think, but I see how to do it now. Disregard that last post.

kowplunk4-Aug-04 11:54

4-Aug-04 11:54

well I got everything working the way that I want to. Thanks again for the help

Jim Matthews4-Aug-04 14:26

4-Aug-04 14:26

no problem, glad it worked out for ya. sorry for the lack of responsiveness, i had left work and have spent the last few hours playing in the backyard with my daughter... some things are more important you know. Smile | :)

just in case though, as for the last post, if you just create multiple tablestyles and give them the appropriate mapping name based on the table you want them to display, the grid will take care of handling everything for you. then you can have the parent table display one way (for example: light blue background) a first child table another (light green background) and a second child table a third (orange background) it's pretty flexible. the ony real downside is the maintenance if columnnames change etc.

take it easy.

-jim

kowplunk9-Aug-04 6:10