SQL Parameter IsNullable

Question

Through the SqlParameter class (for C#) I can see parameters in a stored procedure.

How do you know if a parameter is mandatory or not? I tried using IsNullable but it's always false.

Maybe I'm writing a wrong stored procedure, or is IsNullable meant just to set?

Thanks

NULLABLE is not the same as OPTIONAL. You can have a non-optional but nullable field. You can also have an optional non-nullable field. — MatBailie
– MatBailie, Commented May 22, 2012 at 6:36

Community · Accepted Answer · 2017-05-23 12:20:17Z

2

"Optional" simply means there is a default for stored procedure parameters.
Otherwise, all parameters can be NULL: there is no definition constraint to stop this.

You'd have to parse the stored proc T-SQL to see the default, as per this answer Is there a solution for getting the default value of the parameters of a given stored procedure?

And if you can parse the stored proc definition, then you start to lose the encapsulation benefits

edited May 23, 2017 at 12:20

CommunityBot

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answered May 22, 2012 at 7:07

gbn

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Comments

Nikhil Agrawal · Accepted Answer · 2012-05-22 06:03:10Z

0

In Codebehind use this for checking whether database values are null or not

bool isnull = Convert.IsDBNull(yourvalue);

In SQL use ISNULL (check_expression, replacement_value)

select ISNULL(columnname, 0) from tablename

answered May 22, 2012 at 6:03

Nikhil Agrawal

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1 Comment

lnu Over a year ago

It works for the resultset but here he wants to know if a parameter is mandatory. I don't think there's a way to known if a parameter is mandatory by code but I'm not 100% sure.

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