Programming Forums > Application Development > C#

BungalowBill · Apr 10th, 2006, 5:53 AM

I want to add information to a database using a form. I want to take 3 bits of information - Name, Price, Quantity.
Name must be stored in the DB as text, Price as currency and quantity as Number.

For name ive got:

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string name          = TextBox1.Text;

which works.

For Quantity ive got:

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int quantity         = Int32.Parse(TextBox3.Text);

which i think works.

But i don't know what to do for currency.

I had something like this:

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System.Decimal price = TextBox2.Text;

but it doesn't like it. Do i have to parse it like the int quantity one?

It gives this error: Cannot implicitly convert type 'string' to 'decimal'.

I know what the problem is, i just don't know the correct code.

The Dark · Apr 10th, 2006, 6:47 AM

Yes, parse it like the int one, except use the Decimal.Parse method.

Animatronic · Apr 10th, 2006, 6:52 AM

A decimal is a type just like Int32/float etc... therefore it will have a Parse() method and/or ToString(). On side note why are you using a decimal (an 80bit floating point number) to store price? it seems like overkill.

Ooble · Apr 10th, 2006, 6:53 AM

When parsing data entered by the user, it would probably be better to use the TryParse method. Instead of throwing an exception on failure, this method simply returns false.

Kaja Fumei · Apr 10th, 2006, 12:30 PM

Quote:

Originally Posted by Animatronic

A decimal is a type just like Int32/float etc... therefore it will have a Parse() method and/or ToString(). On side note why are you using a decimal (an 80bit floating point number) to store price? it seems like overkill.

1. decimal is 128 bits.
2. Quote from MSDN: "The Decimal value type is appropriate for financial calculations requiring large numbers of significant integral and fractional digits and no round-off errors." In other words, it uses what's called "decimal arithmetic" so there is no loss of precision like you get with float and doubles.

DaWei · Apr 10th, 2006, 12:47 PM

Lord knows one wouldn't want rounding errors in a dollar-two-ninety-eight! :eek:

nnxion · Apr 10th, 2006, 4:01 PM

Quote:

Originally Posted by DaWei

Lord knows one wouldn't want rounding errors in a dollar-two-ninety-eight! :eek:

Yeah, I don't think a banking application is going to be written in C# anyway. I might be wrong though.

TheCodeLord · Apr 10th, 2006, 4:51 PM

I'd recommend using float... It's proven reliable for me till now

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float price = float.Parse(this.Textbox2.Text);

Then I don't know what DB you're using, coz I've had problems with SQL2000 datatypes before.

BungalowBill · Apr 12th, 2006, 5:36 AM

Thanks for that codelord i'll give that a go. Is the - this. - part neccessary though?

im just using access for the DB.

blank · Apr 13th, 2006, 3:09 AM

I always just do

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decimal thing = Convert.ToDecimal(mystring);

Apr 10th, 2006, 5:53 AM	#1
BungalowBill Programmer Join Date: Dec 2005 Posts: 40 Rep Power: 0	String to decimal. I want to add information to a database using a form. I want to take 3 bits of information - Name, Price, Quantity. Name must be stored in the DB as text, Price as currency and quantity as Number. For name ive got: (Toggle Plain Text) string name = TextBox1.Text; string name = TextBox1.Text; which works. For Quantity ive got: (Toggle Plain Text) int quantity = Int32.Parse(TextBox3.Text); int quantity = Int32.Parse(TextBox3.Text); which i think works. But i don't know what to do for currency. I had something like this: (Toggle Plain Text) System.Decimal price = TextBox2.Text; System.Decimal price = TextBox2.Text; but it doesn't like it. Do i have to parse it like the int quantity one? It gives this error: Cannot implicitly convert type 'string' to 'decimal'. I know what the problem is, i just don't know the correct code.

Apr 10th, 2006, 6:53 AM	#4
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	When parsing data entered by the user, it would probably be better to use the TryParse method. Instead of throwing an exception on failure, this method simply returns false. __________________ Me :: You :: Them

Apr 10th, 2006, 12:47 PM	#6
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	Lord knows one wouldn't want rounding errors in a dollar-two-ninety-eight! :eek: __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Apr 10th, 2006, 4:51 PM	#8
TheCodeLord Newbie Join Date: Apr 2006 Posts: 7 Rep Power: 0	I'd recommend using float... It's proven reliable for me till now (Toggle Plain Text) float price = float.Parse(this.Textbox2.Text); float price = float.Parse(this.Textbox2.Text); Then I don't know what DB you're using, coz I've had problems with SQL2000 datatypes before.

Apr 13th, 2006, 3:09 AM	#10
blank Newbie Join Date: Sep 2005 Posts: 14 Rep Power: 0	I always just do (Toggle Plain Text) decimal thing = Convert.ToDecimal(mystring); decimal thing = Convert.ToDecimal(mystring); __________________ http://www.codeblank.net/ - Coding Forums with Syntax Highlighter and Random Post count http://www.jorgepena.be/ - Personal Site

Apr 10th, 2006, 6:47 AM	#2
The Dark Expert Programmer Join Date: Jun 2005 Posts: 893 Rep Power: 4	Yes, parse it like the int one, except use the Decimal.Parse method.

Apr 10th, 2006, 6:52 AM	#3
Animatronic Programmer Join Date: Jun 2005 Posts: 99 Rep Power: 4	A decimal is a type just like Int32/float etc... therefore it will have a Parse() method and/or ToString(). On side note why are you using a decimal (an 80bit floating point number) to store price? it seems like overkill.

Apr 12th, 2006, 5:36 AM	#9
BungalowBill Programmer Join Date: Dec 2005 Posts: 40 Rep Power: 0	Thanks for that codelord i'll give that a go. Is the - this. - part neccessary though? im just using access for the DB.

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Programming Forums > Application Development > C#

String to decimal.