Retrieving ObjectDataSource columns

[Larry Bud]

I have a simple data object that returns two columns in a dataset, ID
and DESC, for example.

When I bind a dropdownlist to this <dataobjectmeth od>, I have to
manually enter the column names for the ID and value. How do I make
the schema available?

[=?ISO-8859-1?Q?Poli_Garc=EDa?=]

Re: Retrieving ObjectDataSourc e columns

Larry Bud wrote:

I have a simple data object that returns two columns in a dataset, ID
and DESC, for example.
>
When I bind a dropdownlist to this <dataobjectmeth od>, I have to
manually enter the column names for the ID and value. How do I make
the schema available?
>

I don't quite understand what you mean by

How do I make the schema available?

but if what you want is to avoid having to

enter the column names for the ID and value

I think you have no other option rather than specifying the
DataTextField and DataValueField properties of the DropDownList, because
their default values are string.Empty. The only case you can avoid
specifying them is if your DataSource has only one field as specified in

http://msdn2.microsoft.com/en-us/library/31723w77(VS.80).aspx:

If the data source has only one field, you do not have to explicitly
set these fields, because the control will simply display the single field.

Regards

Poli

[=?ISO-8859-1?Q?Poli_Garc=EDa?=]

Re: Retrieving ObjectDataSourc e columns

Poli García wrote:

Larry Bud wrote:

>I have a simple data object that returns two columns in a dataset, ID
>and DESC, for example.
>>
>When I bind a dropdownlist to this <dataobjectmeth od>, I have to
>manually enter the column names for the ID and value. How do I make
>the schema available?
>>

I don't quite understand what you mean by

How do I make the schema available?

but if what you want is to avoid having to

enter the column names for the ID and value

I think you have no other option rather than specifying the
DataTextField and DataValueField properties of the DropDownList, because
their default values are string.Empty. The only case you can avoid
specifying them is if your DataSource has only one field as specified in

http://msdn2.microsoft.com/en-us/library/31723w77(VS.80).aspx:

If the data source has only one field, you do not have to explicitly
set these fields, because the control will simply display the single field.
>
Regards
>
Poli

The link is: http://msdn2.microsoft.com/en-us/lib...77(VS.80).aspx

[Larry Bud]

Re: Retrieving ObjectDataSourc e columns

On Oct 17, 11:44 am, Poli García <poligar...@gma il.comwrote:

Larry Bud wrote:

I have a simple data object that returns two columns in a dataset, ID
and DESC, for example.

>

When I bind a dropdownlist to this <dataobjectmeth od>, I have to
manually enter the column names for the ID and value. How do I make
the schema available?

>
I don't quite understand what you mean by

How do I make the schema available?

but if what you want is to avoid having to

enter the column names for the ID and value

I think you have no other option rather than specifying the
DataTextField and DataValueField properties of the DropDownList, because
their default values are string.Empty. The only case you can avoid
specifying them is if your DataSource has only one field as specified inhttp://msdn2.microsoft .com/en-us/library/31723w77(VS.80) .aspx:
If the data source has only one field, you do not have to explicitly
set these fields, because the control will simply display the single field.

So anytime I bind any data object, such as a GridView, to a
datasourceobjec t, I have to manually specify the column names?

[=?ISO-8859-1?Q?Poli_Garc=EDa?=]

Re: Retrieving ObjectDataSourc e columns

Larry Bud wrote:

On Oct 17, 11:44 am, Poli García <poligar...@gma il.comwrote:

>Larry Bud wrote:

>>I have a simple data object that returns two columns in a dataset, ID
>>and DESC, for example.
>>When I bind a dropdownlist to this <dataobjectmeth od>, I have to
>>manually enter the column names for the ID and value. How do I make
>>the schema available?

>I don't quite understand what you mean by

> How do I make the schema available?

>but if what you want is to avoid having to

> enter the column names for the ID and value

>I think you have no other option rather than specifying the
>DataTextFiel d and DataValueField properties of the DropDownList, because
>their default values are string.Empty. The only case you can avoid
>specifying them is if your DataSource has only one field as specified inhttp://msdn2.microsoft .com/en-us/library/31723w77(VS.80) .aspx:
> If the data source has only one field, you do not have to explicitly
>set these fields, because the control will simply display the single field.

>
So anytime I bind any data object, such as a GridView, to a
datasourceobjec t, I have to manually specify the column names?
>
>
>

Not at all, what I just said applies to DropDownList and the other
ListControls (ie: ListBox, RadioButtonList , CheckBoxList, DropDownList),
with a GridView you can get the columns automatically resolved if you
set the AutoGenerateCol umns property to *true*:

http://msdn2.microsoft.com/en-us/library/system.web.ui.webcontrols.gridview.autogeneratecolumns.aspx

Regards

[Phil H]

Re: Retrieving ObjectDataSourc e columns

On 17 Oct, 16:15, Larry Bud <larrybud2...@y ahoo.comwrote:

I have a simple data object that returns two columns in a dataset, ID
and DESC, for example.
>
When I bind a dropdownlist to this <dataobjectmeth od>, I have to
manually enter the column names for the ID and value. How do I make
the schema available?

ObjectDataSourc es do not present database schema information at Design
Time in the same way as SQl or XML sources. The output from code
behind ObjectDatasourc es cannot be inferred by the designer. Like all
other objects and data that are created in code their output is
entirely unknown to the system until run-time.

HTH

[Larry Bud]

Re: Retrieving ObjectDataSourc e columns

On Oct 17, 2:45 pm, Phil H <goo...@philpha ll.me.ukwrote:

On 17 Oct, 16:15, Larry Bud <larrybud2...@y ahoo.comwrote:
>

I have a simple data object that returns two columns in a dataset, ID
and DESC, for example.

>

When I bind a dropdownlist to this <dataobjectmeth od>, I have to
manually enter the column names for the ID and value. How do I make
the schema available?

>
ObjectDataSourc es do not present database schema information at Design
Time in the same way as SQl or XML sources. The output from code
behind ObjectDatasourc es cannot be inferred by the designer. Like all
other objects and data that are created in code their output is
entirely unknown to the system until run-time.

Thanks, glad to know I wasn't going nuts. I was hoping there was
some way to define what the columns would be, but I guess not.

[Larry Bud]

Re: Retrieving ObjectDataSourc e columns

On Oct 17, 2:14 pm, Poli García <poligar...@gma il.comwrote:

Larry Bud wrote:

On Oct 17, 11:44 am, Poli García <poligar...@gma il.comwrote:

Larry Bud wrote:
>I have a simple data object that returns two columns in a dataset, ID
>and DESC, for example.
>When I bind a dropdownlist to this <dataobjectmeth od>, I have to
>manually enter the column names for the ID and value. How do I make
>the schema available?
I don't quite understand what you mean by
How do I make the schema available?
but if what you want is to avoid having to
enter the column names for the ID and value
I think you have no other option rather than specifying the
DataTextField and DataValueField properties of the DropDownList, because
their default values are string.Empty. The only case you can avoid
specifying them is if your DataSource has only one field as specified inhttp://msdn2.microsoft .com/en-us/library/31723w77(VS.80) .aspx:
If the data source has only one field, you do not have to explicitly
set these fields, because the control will simply display the single field.

>

So anytime I bind any data object, such as a GridView, to a
datasourceobjec t, I have to manually specify the column names?

>
Not at all, what I just said applies to DropDownList and the other
ListControls (ie: ListBox, RadioButtonList , CheckBoxList, DropDownList),
with a GridView you can get the columns automatically resolved if you
set the AutoGenerateCol umns property to *true*:http://msdn2.microsoft.com/en-us/lib...webcontrols.gr...

Sure, but not at design time. If I wanted to create template fields,
I'll have to do so manually.