.net – Am I opening and closing the ODBC connection incorrectly

netodbcsap-asevb.net

When connecting to a Sybase ASE database via ODBC using the code below, I'll occasionally get a '[IM006] [Microsoft][ODBC Driver Manager] Driver's SQLSetConnectAttr failed' error.

Can this be caused by my code? I read here that I should be using the 'With' statement instead, but I don't understand how that would affect this.

Thanks in advance!

    Try
        odsConn.Open()
        Dim acctCheckString As String = sB.ToString
        Dim odsCmd As New OdbcCommand(acctCheckString, odsConn)

        odsRtrn = CStr(odsCmd.ExecuteScalar).TrimEnd
    Catch ex As Exception
        odsRtrn = ex.Message.ToUpper
        odsRtrn = CheckError(odsRtrn)
    Finally
        odsConn.Close()
    End Try

Best Answer

I apologize for interjecting without an answer to your specific question, but if I might make a suggestion...

In the year 2009, if you are using vb.Net, and you are still using ODBC, you should please (seriously) check out ADO.Net managed code data providers. There is one for Sybase...

SyBase ADO.Net Providers

This will completely replace the odbc libraries. they are much easier to use.

This is the style that Microsoft tends to use in their examples.

It appears that the guidance in this area may have changed, as StyleCop now enforces the use of the C# specific aliases.

.net – Difference between decimal, float and double in .NET

float and double are floating binary point types. In other words, they represent a number like this:

10001.10010110011

The binary number and the location of the binary point are both encoded within the value.

decimal is a floating decimal point type. In other words, they represent a number like this:

12345.65789

Again, the number and the location of the decimal point are both encoded within the value – that's what makes decimal still a floating point type instead of a fixed point type.

The important thing to note is that humans are used to representing non-integers in a decimal form, and expect exact results in decimal representations; not all decimal numbers are exactly representable in binary floating point – 0.1, for example – so if you use a binary floating point value you'll actually get an approximation to 0.1. You'll still get approximations when using a floating decimal point as well – the result of dividing 1 by 3 can't be exactly represented, for example.

As for what to use when:

For values which are "naturally exact decimals" it's good to use decimal. This is usually suitable for any concepts invented by humans: financial values are the most obvious example, but there are others too. Consider the score given to divers or ice skaters, for example.
For values which are more artefacts of nature which can't really be measured exactly anyway, float/double are more appropriate. For example, scientific data would usually be represented in this form. Here, the original values won't be "decimally accurate" to start with, so it's not important for the expected results to maintain the "decimal accuracy". Floating binary point types are much faster to work with than decimals.

Best Answer

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C# – the difference between String and string in C#

This is the style that Microsoft tends to use in their examples.

.net – Difference between decimal, float and double in .NET

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