Unable to insert decimal

Question

1.00/5 (1 vote)

See more:

i am not able to insert decimal value in c# using .net framework.
every time these error is coming

An unhandled exception of type 'System.InvalidCastException' occurred in mscorlib.dll

Additional information: Unable to cast object of type 'System.Data.SqlClient.SqlParameter' to type 'System.IConvertible'.

table

CREATE TABLE [dbo].[itemmaster]
(
	[itemcode] [varchar](33) NULL,
	[name] [varchar](50) NULL,
	[salesprice] [decimal](18, 2) NULL,
	[salestax] [decimal](18, 2) NULL,
	[profit] [decimal](18, 2) NULL,
	[quantityonhand] [decimal](18, 2) NULL
) ON [PRIMARY]

What I have tried:

SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=DelhiEMP;Integrated Security=True");
            SqlCommand cmd = new SqlCommand("insert into itemmaster(itemcode,name) values(@itemcode,@name)", con);
            con.Open();
            itemmaster itemmastr = new itemmaster();
            itemmastr.itemcode = Convert.ToString(cmd.Parameters.AddWithValue("@itemcode", txtitemcode.Text.Trim()));
            itemmastr.name = Convert.ToString(cmd.Parameters.AddWithValue("@name", txtname.Text.Trim()));
            itemmastr.salesprice = Convert.ToDecimal(cmd.Parameters.AddWithValue("@salesprice", txtsaleprice.Text));
            
           
            SqlDataAdapter da = new SqlDataAdapter(cmd);  
            DataSet ds = new DataSet();
            da.Fill(ds, "itemmaster");
            dataGridView1.DataSource = null;

Posted 21-May-17 19:58pm

faizy001

Updated 21-May-17 20:22pm

Add a Solution

Comments

Maciej Los 22-May-17 2:30am

What are you trying to achieve?

3 solutions

Add a Solution

Add your solution here

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.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Answer 1 · 2017-05-21T20:20:00

Please, do yourself a favour, and look at the documentation.
You should be converting user input to native types first (with error handling to report problems to the user) and then passing the native values to SQL via cmd.Parameters.AddWithValue.

That code looks like you guessed what to put and hoped for the best rather than looking up the function (which include examples) and implementing them.

Michael_Davies · Answer 2 · 2017-05-21T20:10:00

I suspect adding parameters to an SqlCommand does not return the value added. You would be better to convert your values into itemmastr then add the parameters from itemmastr. Also no need to convert to string what is already a string.

Cannot see the rest of your code for the decimal field you must also be certain that the data entered is a number, better to use decimal.tryparse to verify first and stop if it fails.

C#

itemmastr.itemcode = txtitemcode.Text.Trim();
itemmastr.name = txtname.Text.Trim();
itemmastr.salesprice = Convert.ToDecimal(txtsaleprice.Text);

cmd.Parameters.AddWithValue("@itemcode", itemmastr.itemcode);
cmd.Parameters.AddWithValue("@name", itemmastr.name);
cmd.Parameters.AddWithValue("@salesprice", itemmastr.salesprice);

Forgot to add:
Your insert command does not include salesprice, it only inserts itemcode and name so you'll still get a failure on the cmd.parameters line for salesprice.

Robert Welliever · Answer 3 · 2017-05-21T20:21:00

Void routines do not return values. You are trying to pass a non-existent return value to the Convert class. Your command object for an insert should look like more like this:

using (SqlConnection connection = new SqlConnection("Data Source=.;Initial Catalog=DelhiEMP;Integrated Security=True")){
                using (SqlCommand command = new SqlCommand("insert into itemmaster(itemcode,name) values(@itemcode,@name)", connection))
                {
                    command.Parameters.AddWithValue("@itemcode", txtitemcode.Text.Trim());
                    command.Parameters.AddWithValue("@name", txtname.Text.Trim());
                    command.Parameters.AddWithValue("@salesprice", txtsaleprice.Text);
                    connection.Open();
                    command.ExecuteNonQuery();
                    connection.Close();
                }
            }

The use of itemmaster has me confused on what your goal is. Also opening the db connection before you finish creating your command object is incorrect, and the assignment of null to to dataGridView1.DataSource doesn't necessarily seem like a great way to populate a datagrid.

Unable to insert decimal

3 solutions

Solution 2

Solution 1

Solution 3

Add your solution here

Preview 0