ASP.NET DropDownList Default Value As "NULL"

Question

Hi Experts,

I have Patient details form. From that I am storing the data to DB using Stored Procedure.

In table, all fields are allowed null except Primary key.

When I store data, then I will stored using .Text property.

For non-mandatory field, if text box value is "" then it will stored, but in case DropDownList if I pass empty string ("") to DB then it will show me error as

"Input string was not in correct format"   

Why?

I have used DropDownList's SelectedItem.Text and SelectedValue . But in both case it show me the same error.

Is there any case to pass default value of DropDown value as NULL?

Or any other idea?

Note : I am using LINQ. (.NET FW 3.5) and SQL Server 2008.

Thanks.

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"Knowledge Shared Is Knowledge Gained"

Answer 1

Pass a DbNull (namespace: System)

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Ganesh Ranganathan
[Please mark the post as answer if it answers your question]
blog.ganeshzone.net

Answer 2

Hi Ganesh,

Thanks for the reply.

Can't get you.

Will you explain it in details?

Thanks.

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"Knowledge Shared Is Knowledge Gained"

Answer 3

Ok Ganesh.

I got it man!

But I don't want to hard code it while storing to DB.

If there is some value for DropDown then makes problem.

Or while storing to SP, I need to check it whether it is NULL or not?

Right?

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"Knowledge Shared Is Knowledge Gained"

Answer 4

Hi Ganesh,

Tried it but not working while passing value as DbNull.

I think this is due to mis-match of Data Type.

Any solution ?

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"Knowledge Shared Is Knowledge Gained"

Answer 5

Hi All,

Got it.

Please check the following URL :

http://forums.asp.net/p/1532814/3715059.aspx#3715059

Thanks.

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"Knowledge Shared Is Knowledge Gained"