Can a boolean data type be null?
I'm passing a parameter to a stored procedure. It's type is defined by the
line:
....
SqlParameter paramOK = cmd.Parameters.Add("@IsOK",
SqlDbType.Bit);
....
and it's value is set using:
....
paramIsOK.Value = null;
....
but it doesn't like this (I'd like to have the null possibility if a user
has neither replied Yes nor No to a question on a form.)
many thanks
Pete
6  10591 
Italian Pete wrote: Can a boolean data type be null?
Not quite.
I'm passing a parameter to a stored procedure. It's type is defined by the
line:
...
SqlParameter paramOK = cmd.Parameters.Add("@IsOK",
SqlDbType.Bit);
...
and it's value is set using:
...
paramIsOK.Value = null;
...
but it doesn't like this (I'd like to have the null possibility if a user
has neither replied Yes nor No to a question on a form.)
C#'s 'null' is not the same thing as SQL's 'NULL'. The former is an
object reference to no object at all; the latter is a value of a
database field. You want
paramIsOK.Value = DBNull.Value;
--
Larry Lard
Replies to group please
Italian Pete wrote: Can a boolean data type be null?
Not quite.
I'm passing a parameter to a stored procedure. It's type is defined by the
line:
...
SqlParameter paramOK = cmd.Parameters.Add("@IsOK",
SqlDbType.Bit);
...
and it's value is set using:
...
paramIsOK.Value = null;
...
but it doesn't like this (I'd like to have the null possibility if a user
has neither replied Yes nor No to a question on a form.)
C#'s 'null' is not the same thing as SQL's 'NULL'. The former is an
object reference to no object at all; the latter is a value of a
database field. You want
paramIsOK.Value = DBNull.Value;
--
Larry Lard
Replies to group please
Hi,
"Italian Pete" <It*********@discussions.microsoft.com> wrote in message
news:A4**********************************@microsof t.com... Can a boolean data type be null?
In a DB yes , there is no bool in SQL server, there is BIT and yes, it can
accept nulls
I'm passing a parameter to a stored procedure. It's type is defined by the
line:
...
SqlParameter paramOK = cmd.Parameters.Add("@IsOK",
SqlDbType.Bit);
...
and it's value is set using:
...
paramIsOK.Value = null;
...
but it doesn't like this (I'd like to have the null possibility if a user
has neither replied Yes nor No to a question on a form.)
Of course he does not like it, If you use DBNull.Value it will be pleased :)
For your case you could have a short int , with values 1, 2, 3 where each
one mean , yes, no , no answer
I alwasy try to avoid dealing with nulls :)
cheers,
--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation
Hi,
"Italian Pete" <It*********@discussions.microsoft.com> wrote in message
news:A4**********************************@microsof t.com... Can a boolean data type be null?
In a DB yes , there is no bool in SQL server, there is BIT and yes, it can
accept nulls
I'm passing a parameter to a stored procedure. It's type is defined by the
line:
...
SqlParameter paramOK = cmd.Parameters.Add("@IsOK",
SqlDbType.Bit);
...
and it's value is set using:
...
paramIsOK.Value = null;
...
but it doesn't like this (I'd like to have the null possibility if a user
has neither replied Yes nor No to a question on a form.)
Of course he does not like it, If you use DBNull.Value it will be pleased :)
For your case you could have a short int , with values 1, 2, 3 where each
one mean , yes, no , no answer
I alwasy try to avoid dealing with nulls :)
cheers,
--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation
By definition a bool must either be true or false. However, in version 2.0
of the .NET framework, MS will implement "nullable types." With this you
would, essentially, be able to declare a tri-state bool that can be either
true, false, or (I think) null. (If not null, then undefined). If you're
interested in more info on this check MS's web site. (Sorry I don't have the
correct link, but I'd start at "http://msdn.microsoft.com/vs2005".
..ARN.
"Italian Pete" wrote: Can a boolean data type be null?
I'm passing a parameter to a stored procedure. It's type is defined by the
line:
...
SqlParameter paramOK = cmd.Parameters.Add("@IsOK",
SqlDbType.Bit);
...
and it's value is set using:
...
paramIsOK.Value = null;
...
but it doesn't like this (I'd like to have the null possibility if a user
has neither replied Yes nor No to a question on a form.)
many thanks
Pete
By definition a bool must either be true or false. However, in version 2.0
of the .NET framework, MS will implement "nullable types." With this you
would, essentially, be able to declare a tri-state bool that can be either
true, false, or (I think) null. (If not null, then undefined). If you're
interested in more info on this check MS's web site. (Sorry I don't have the
correct link, but I'd start at "http://msdn.microsoft.com/vs2005".
..ARN.
"Italian Pete" wrote: Can a boolean data type be null?
I'm passing a parameter to a stored procedure. It's type is defined by the
line:
...
SqlParameter paramOK = cmd.Parameters.Add("@IsOK",
SqlDbType.Bit);
...
and it's value is set using:
...
paramIsOK.Value = null;
...
but it doesn't like this (I'd like to have the null possibility if a user
has neither replied Yes nor No to a question on a form.)
many thanks
Pete This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics
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