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Cannot Convert Dbnull To String C#


This is from the cast to string on the first line: string accountNumber = (string) ... On 1941 Dec 7, could Japan have destroyed the Panama Canal instead of Pearl Harbor in a surprise attack? The 10'000 year skyscraper Can I hint the optimizer by giving the range of an integer? well helps:public static object ReadNullIfDbNull(IDataReader reader, intcolumn){object value = reader.GetValue(column);return value == DbNull.Value ? http://txtbl.com/unable-to/cannot-convert-system-dbnull-to-string.html

But the return type is of system.dbnull. This would be something like: string value = ( from row in ds.Tables[0].Rows select row.Field(0) ).FirstOrDefault(); share|improve this answer answered Aug 25 '08 at 20:47 Keith 67.2k39185293 2 +1: this If you have needs for an explicit cast, don't use this function - do it explicitly instead. –rein Oct 7 '14 at 22:44 | show 7 more comments up vote 14 A lot to learn, especially when comming from a very differnt programming background Robert "Dave Sexton"

Unable To Cast Object Of Type 'system.dbnull' To Type 'system.string'. C#

PropertyInfo.Name will never return DBNull.Value. –Rune FS May 23 '10 at 11:35 | show 1 more comment Your Answer draft saved draft discarded Sign up or log in Sign up c# .net sql-server share|improve this question edited Mar 14 at 9:58 Mark 958420 asked Aug 25 '08 at 20:36 Mykroft 5,672113363 close: most-efficient-way-to-check-for-dbnull-and-then-assign-to-a-‌variable –nawfal Dec 11 '13 at 16:42 string.Empty : erow.SNO.ToString() share|improve this answer answered May 17 '12 at 7:55 Blachshma 12.8k42952 1 Actually the second option will work –Emad Mokhtar May 17 '12 at 11:16 How can I convert that toa system.stingThanksRobert Dec 3 '06 #10 This discussion thread is closed Start new discussion Replies have been disabled for this discussion.

In it, you'll get: The week's top questions and answers Important community announcements Questions that need answers see an example newsletter By subscribing, you agree to the privacy policy and terms Not the answer you're looking for? Mea culpa. –User May 15 '09 at 20:28 1 Yep, now you're talking! :-) –marc_s May 15 '09 at 20:29 There is typo in your post that I Unable To Cast Object Of Type System Dbnull To Type System Byte Vb Net Robert "Stefan Delmarco"

I should have added, there are 3 ways to configure your typed dataset's handling of null values (per column): - Throw an exception if a null is encountered (the default) - share|improve this answer answered Feb 10 '09 at 21:33 Simon 17.6k986137 We are using ORM now. But the return type is of system.dbnull. How can I convert that to a system.sting Thanks Robert Dec 2 '06 #1 Post Reply Share this Question 9 Replies P: n/a Dave Sexton Hi Robert, object value = row["column"];

Why does Friedberg say that the role of the determinant is less central than in former times? Dbnull In C# Example Solutions? Join them; it only takes a minute: Sign up Unable to cast object of type System.DBNull to type System.String [duplicate] up vote 0 down vote favorite This question already has an That being said, if you are on an older version of the framework or work for someone who doesn't grok nullable types, the code example will do the trick.

The Value For Column In Table Is Dbnull C#

It is good to know. Why cast an A-lister for Groot? Unable To Cast Object Of Type 'system.dbnull' To Type 'system.string'. C# I was assuming you were iterating over an IDataReader. Cannot Implicitly Convert Type 'system.dbnull' To 'string' DataRow row = ds.Tables[0].Rows[0]; string value; if (row["fooColumn"] == DBNull.Value) { value = string.Empty; } else { value = Convert.ToString(row["fooColumn"]); } this becomes: DataRow row = ds.Tables[0].Rows[0]; string value = row.ToString()

string.Empty : erow.SNO.ToString() it is Showing Cannot be applied of Type int –ebbicsku May 17 '12 at 13:58 What is the type of SNO column in the DB? –Blachshma If you hjust want to use empty string you could just call .ToString() on value in the above example SetValue(this, value.ToString(),null) –Rune FS May 23 '10 at 11:40 add a comment| Is it safe to use cheap USB data cables? Linked 60 Unable to cast object of type 'System.DBNull' to type 'System.String` Related 60Unable to cast object of type 'System.DBNull' to type 'System.String`2RowDataBound : Getting value from dataTable ! Unable To Cast Object Of Type 'system.dbnull' To Type 'system.byte '

What is the simplest way to put some text at the beginning of a line and to put some text at the center of the same line? Cheers, Stefan Delmarco http://www.fotia.co.uk Hello Robert, From the code snippet it looks like you're using a strongly typed data set. string.Empty (genuine question I don't know the answer) –Martin Smith May 23 '10 at 11:15 unfortunately it wouldn't it's strictly for null-values and since DBNull.Value is an object it string.Empty; , with accountNumber still being an object.

asked 1 year ago viewed 450 times active 1 year ago Related 3836What is the difference between String and string in C#?308How to convert a column number (eg. 127) into an Convert.tostring Dbnull cmd.CommandText = "Select * From Responses"; cmd.CommandType = CommandType.Text; cmd.Connection = conn; // Retrieve data reader. Any reason you are not using an ORM?

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dont use "as", "convert", "parse" or "tostring" // as all of these will swallow the case where is the incorect type. // (Unless it is a string in the DB and I've seen that this question has been asked a couple times and it seems like I should just do a check to see if null before it converts it and enters if(!dbReader.IsDBNull(5)) aPartOrder.VendorId = dbReader.GetString(5); Suggestion: Always use parameters/precompiled sql statement to prevent SQL-Injection attack. System.dbnull Check Treat my content as plain text, not as HTML Preview 0 … Existing Members Sign in to your account ...or Join us Download, Vote, Comment, Publish.

I bet that the "NullValue" property for the FirstNamecolumn is "(Throw)". I bet that the "NullValue" property for the FirstName column is "(Throw)". share|improve this answer answered Aug 25 '08 at 20:45 Pascal Paradis 3,14352644 add a comment| up vote 1 down vote For some reason I've had problems with doing a check against If PropertyItem.Name can be null or PropertyItem.SetValue can't accept a null value then you have to check on every loop.

PropertyItem.Name is reflection oriented rather than DB oriented so I'd be surprised if it would use DbNull.Value rather than just null. –Martin Smith May 23 '10 at 11:11 Gotta Browse more C# / C Sharp Questions on Bytes Question stats viewed: 30139 replies: 9 date asked: Dec 2 '06 Follow this discussion BYTES.COM © 2016 Formerly "TheScripts.com" from 2005-2008 About Unable to cast object of type 'System.DBNull' to type 'System.String'3Unable to cast object of type 'System.DBNull' to type 'System.String'0Unable to cast object of type 'System.DBNull' to type 'System.String'. This way when you scroll up/down your datagridview, the text boxes would be updated automatically.

Have a look at the XSD for your dataset (or have a look at it in the DataSet designer). If you know that the first column of the resultset is a string, then to cover all bases you need to check for both null and DBNull. Player claims their wizard character knows everything (from books). Was a massive case of voter fraud uncovered in Florida?

In your case the error message "Unable to cast object of type ‘System.DBNull’ to type ‘System.String`" indicates that the first column of your result set is a DBNUll value. How to tar.gz many similar-size files into multiple archives with a size limit Is it unethical to poorly translate an exam from Dutch to English and then present it to the string.Empty; The 'as' operator returns null for invalid cast's, like DBNull to string, and the '??' returns the term to the right of the expression if the first is null. Linux questions C# questions ASP.NET questions fabric questions SQL questions discussionsforums All Message Boards...

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