How to use a string that stores integer values (result of a SQL query)?

I am using C# and SQL Server.

I have to retrieve the prices of particular products from a table and make use of these values later for computation.

For eg.

I use the following query and store it in a string.

string str = " select cat_price from category where cat_item开发者_运维问答ID= 'A001'" ;

Now I need this particular value retrieved here to be stored in a variable for further computation

for eg.

int price_amount;

and I need to use mathematical operations. How do I do this?

Use the ExecuteScalar method of a SqlCommand to get the first value:

using (SqlConnection cn = new SqlConnection(...))
{
    using (SqlCommand cmd = new SqlCommand(cn, "select cat_price from category where cat_itemID= 'A001'"))
    {
        //Execute the query and just get the first result.
        int value = (int)cmd.ExecuteScalar();
    }
}

You can use SQLDbConnection and ExecuteScaler to get get this out of the DB if that is your question. Below is a link to do this.

http://www.codeproject.com/KB/database/sql_in_csharp.aspx