John W. Colby
jwcolby at colbyconsulting.com
Wed May 26 08:13:11 CDT 2004
Susan, >Yes, years ago, field length was an issue because of memory -- it no longer is. And yet this very argument has been raised! >On the other hand, JC, it is perfectly acceptable to use field size to limit values. I have no issue with "Can limit the field size". I have an issue with an arbitrary length that MAY limit valid data entry (I thought I had said that). If you are designing something like a state table, and the state table will only hold US states, you can pretty safely limit the code field to 2 characters. It takes no time to figure that out, it takes no time to implement etc. Go for it. If you want to spend your time setting fields like City to 50 characters, go for it. Setting it to 15 I would argue with. Once we go there then what is a valid value? How much time to you spend (and bill the customer for) figuring out EXACTLY the right amount? What if you're wrong? But if that floats your boat, and your customer is willing to pay for it, then by all means go for it. John W. Colby www.ColbyConsulting.com -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com]On Behalf Of Susan Harkins Sent: Wednesday, May 26, 2004 7:59 AM To: 'Access Developers discussion and problem solving' Subject: RE: [AccessD] On DB Bloat, Bad DB Design, and various If I may... What makes either of you think that the other isn't correct in his own right? This is an issue that simply doesn't have a right or wrong. Yes, years ago, field length was an issue because of memory -- it no longer is. No one cares about that anymore unless they're working with a tremendously large amount of data -- and then, they're probably not using Access. On the other hand, JC, it is perfectly acceptable to use field size to limit values. You may not do it, but it is perfectly acceptable. I could take your logic another step and say why bother with data types? I can make the data anything I want using the right conversion function and code, so why bother? Access trainers still teach people that they CAN limit the field's size. It's there, you can use it or not use it. There's nothing wrong with doing so. You're both right -- and you should both use the tools you have the best you can. Period. Susan H. >I'm the expert. No argument. >Quite often the client doesn't know what he/she needs. No argument. >If there would be a good reason to limit a text field to 53 chars, I >would tell or simply apply it. No argument. IF THERE WERE GOOD REASON. >As some examples, ISO country codes are either two or three chars, BIC(SWIFT) codes are 8 or 11 chars, and IBAN codes are, by definition, max. 34 chars - anything above these numbers would represent an error and would make no sense to store. If you are not using a lookup table for this then you have issues. I will hand you this one I suppose, so lookup tables may in certain circumstances be limited. We are assuming here that we suspect the user will be writing books in the country code fields if we don't get out the handcuffs? >Here, no city name is longer than 20 chars and no street name is longer than 34 chars. Today. >Thus 50 is a reasonable limit for domestic address lines which, by the >way, is also what Access's table designer suggests. Do I look impressed with what Access table designer suggests? John W. Colby www.ColbyConsulting.com -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com]On Behalf Of Gustav Brock Sent: Wednesday, May 26, 2004 7:17 AM To: Access Developers discussion and problem solving Subject: Re: [AccessD] On DB Bloat, Bad DB Design, and various Hi John > I keep asking (and nobody is responding) - whose data is it? Whose database > is it. In most cases, the client's. > Who are YOU to TELL the client that 53 characters is all they need? I'm the expert. Quite often the client doesn't know what he/she needs. If there would be a good reason to limit a text field to 53 chars, I would tell or simply apply it. As some examples, ISO country codes are either two or three chars, BIC (SWIFT) codes are 8 or 11 chars, and IBAN codes are, by definition, max. 34 chars - anything above these numbers would represent an error and would make no sense to store. Here, no city name is longer than 20 chars and no street name is longer than 34 chars. Thus 50 is a reasonable limit for domestic address lines which, by the way, is also what Access's table designer suggests. /gustav -- _______________________________________________ AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- _______________________________________________ AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- _______________________________________________ AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com