RE: Help: Can arrays be used like queries
Chris Evans wrote: 1) I don't use just lists. I just tend to use lists rather than arrays. I love using structures :). 3) I'm getting to run some speed tests to prove Nick's comment about speed increases of arrays over lists. That is a good reason to use arrays over lists. sorry for the belated response...but i wasn't arguing with you chris! :) just wanted to see some code. always interested in learning new ways to do things. if you come up with some benchmark numbers, could you share, please? thanks! -emily -- Archives: http://www.eGroups.com/list/cf-talk To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body.
RE: Help: Can arrays be used like queries
Emily, A couple of points: 1) I don't use just lists. I just tend to use lists rather than arrays. I love using structures :). 2) In the shopping bag example, for the store, the key would be the users session ID. I could do it with lists if I wanted. Remember, a 3-dimensional array is nothing more than an array of arrays of arrays. Since a 1- dimensional array is really a list, I could (and have) create a list of lists of lists. I wouldn't do that now, but I would have a version or two ago. 3) I'm getting to run some speed tests to prove Nick's comment about speed increases of arrays over lists. That is a good reason to use arrays over lists. The biggest annoyance I have with arrays is that there always seems to be a lot of looping and other programming overhead involved. I do some programming in C++ and Java, and use arrays and looping in those languages, but in CF that creates a lot of overhead. Chris Evans [EMAIL PROTECTED] http://www.fuseware.com -Original Message- From: Emily B. Kim [mailto:[EMAIL PROTECTED]] Sent: Wednesday, April 05, 2000 12:14 AM To: [EMAIL PROTECTED] Subject: RE: Help: Can arrays be used like queries Hopefully not any different than the way you would do it in an array. In your example below, I would have a structure for Product 1, a structure for Product 2, and so on. I would also have an ItemInYourBag structure, with the key being the product ID and the value being the quantity. If the product had more attributes, such as color or size, they would just be more members of the ItemInYourBag structure. The only list I would maintain would be the list of items in your bag, which is the same as the StructKeyList(ItemInYourBag). I don't think this helped explain why I prefer lists rather than arrays, as my solution would be structures of structures. yeah, i think that you can't do something that complex with just lists. you would have to work with arrays and/or structures. the only "problem" i can see with the structure of structures you have above has to do with what would you be using as your key for the outer structure? you would have to dynamically generate it, which seems like it would be more effort than just using the index that is inherent in an array. -emily -- Archives: http://www.eGroups.com/list/cf-talk To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body. -- Archives: http://www.eGroups.com/list/cf-talk To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body.
RE: Help: Can arrays be used like queries
David, You can also use queries as arrays. For example, if I have a query called "Articles" with a column named "TITLE", and I want the 5th row, I can use Articles.Title[5]. I rarely see a need for arrays with CF, though other programmers seem to use them for everything. I don't quite understand that. I've seen a lot of programming, even custom tags, that translate native CF data elements into arrays, when it is easier to use the native data element. Chris Evans [EMAIL PROTECTED] http://www.fuseware.com -Original Message- From: David Cummins [mailto:[EMAIL PROTECTED]] Sent: Monday, April 03, 2000 7:10 PM To: [EMAIL PROTECTED] Subject: Help: Can arrays be used like queries Hi all, I don't know if this is possible, but can arrays or any other ColdFusion structures be used like queries, i.e. cfoutput query="arrayorsomething", or converted to a query? It's just that it could be a pain converting pages that were initially created to use queries to use loops on arrays instead, and named columns make for more programmer-friendly pages. TIA David Cummins Ubiquity Software Ltd. -- Archives: http://www.eGroups.com/list/cf-talk To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body. -- Archives: http://www.eGroups.com/list/cf-talk To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body.
Re: Help: Can arrays be used like queries
You can also use queries as arrays. For example, if I have a query called "Articles" with a column named "TITLE", and I want the 5th row, I can use Articles.Title[5]. just a fyi, although you can use array syntax to reference queries, remember that queries are NOT arrays so you can't use the array functions on them. I rarely see a need for arrays with CF, though other programmers seem to use them for everything. I don't quite understand that. I've seen a lot of programming, even custom tags, that translate native CF data elements into arrays, when it is easier to use the native data element. arrays are very useful for passing information without having to write to the DB. think of use of an array of structures for a shopping cart. -emily -- Archives: http://www.eGroups.com/list/cf-talk To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body.
RE: Help: Can arrays be used like queries
I always end up using lists rather than arrays, though a list can be thought of as a 1-dimensional array. So I would use a list of structures rather than an array of structures. I find Lists easier to create and maintain than arrays. Chris Evans [EMAIL PROTECTED] http://www.fuseware.com -Original Message- From: Emily B. Kim [mailto:[EMAIL PROTECTED]] Sent: Tuesday, April 04, 2000 10:39 AM To: [EMAIL PROTECTED] Subject: Re: Help: Can arrays be used like queries You can also use queries as arrays. For example, if I have a query called "Articles" with a column named "TITLE", and I want the 5th row, I can use Articles.Title[5]. just a fyi, although you can use array syntax to reference queries, remember that queries are NOT arrays so you can't use the array functions on them. I rarely see a need for arrays with CF, though other programmers seem to use them for everything. I don't quite understand that. I've seen a lot of programming, even custom tags, that translate native CF data elements into arrays, when it is easier to use the native data element. arrays are very useful for passing information without having to write to the DB. think of use of an array of structures for a shopping cart. -emily -- Archives: http://www.eGroups.com/list/cf-talk To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body. -- Archives: http://www.eGroups.com/list/cf-talk To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body.
RE: Help: Can arrays be used like queries
I don't have any exact figures. Ben Forta did a session on Advanced Tips and Tricks, and that was one of them. It was related to the fact that a list is essentially a string, and ColdFusion has to read through that string to find the next delimiter. Every time you wanted to access an element, it had to go through the list checking each character to see if it is the delimiter or not (at least that is my understanding.. I'll recheck my notes!) One of the questions that was asked was whether it would be better to convert to an array and then work on the array until you were done, and then put it back out to the list... the answer to that was yes. So if you must use lists, and need to do much work with them in a script, convert to an array first. Lists are best used for Form results (ie, multiple selects) and in a SQL WHERE clause (ie, WHERE xx IN (#listname#)). Arrays are faster than lists, but Structures are the fastest And if you need to do much work with a single element (this goes for lists, arrays and struct), then copy that element out to a normal variable before doing anything else, and re-add it to the list when finished with it. Maybe if I get the time, I'll go through all the notes I took and post a message of Tips and Tricks!! There are lots of obvious ones.. 1) Reduce the number of db calls, for example, use stored procedures and triggers, referential integrity (and CFTRY/CFCATCH to catch the database errors, this is quicker than letting CF process the forms for errors). 2) CFLOOP vs CFOUTPUT was another... CFLOOP is faster than CFOUTPUT... however, as a rule of thumb, if you are only listing fields from the recordset in CFOUTPUT, then use that. If you are doing additional work, then use CFLOOP. 3) Use CFPARAM, rather than checking for Defined/Null. 4) Evaluate/DE are VERY intensive. Use wisely! 5) Custom Tags are recommended over Includes because of the scope of variables... include files take the parent's scope, and so if you edit an include file, that is used on many pages, and add a new variable... results could be unpredictable if you have already used that same variable name elsewhere. etc etc etc etc :^) Nick At 18:00 4/04/00 -0400, you wrote: Really! That's the first I heard of that. I always thought that Lists would be faster. I always see code where users convert list to arrays, and I would expect that would be more overhead. Do you ( or anybody) have any more detail on performance gain of arrays over lists? Chris Evans [EMAIL PROTECTED] http://www.fuseware.com -Original Message- From: Nick Slay [mailto:[EMAIL PROTECTED]] Sent: Tuesday, April 04, 2000 5:24 PM To: [EMAIL PROTECTED] Subject: RE: Help: Can arrays be used like queries Hi Chris... Just thought I'd mention this tip that I picked up from ColdFusion-master Ben Forta at a developer conference a few weeks back 'Try and avoid using lists. They are a lot slower than Array's or Structures. They are easier to use, but at a cost to performance.' Regards Nick At 10:56 4/04/00 -0400, you wrote: I always end up using lists rather than arrays, though a list can be thought of as a 1-dimensional array. So I would use a list of structures rather than an array of structures. I find Lists easier to create and maintain than arrays. Chris Evans [EMAIL PROTECTED] http://www.fuseware.com -Original Message- From: Emily B. Kim [mailto:[EMAIL PROTECTED]] Sent: Tuesday, April 04, 2000 10:39 AM To: [EMAIL PROTECTED] Subject: Re: Help: Can arrays be used like queries You can also use queries as arrays. For example, if I have a query called "Articles" with a column named "TITLE", and I want the 5th row, I can use Articles.Title[5]. just a fyi, although you can use array syntax to reference queries, remember that queries are NOT arrays so you can't use the array functions on them. I rarely see a need for arrays with CF, though other programmers seem to use them for everything. I don't quite understand that. I've seen a lot of programming, even custom tags, that translate native CF data elements into arrays, when it is easier to use the native data element. arrays are very useful for passing information without having to write to the DB. think of use of an array of structures for a shopping cart. -emily --- - -- Archives: http://www.eGroups.com/list/cf-talk To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body. --- --- Archives: http://www.eGroups.com/list/cf-talk To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsub
RE: Help: Can arrays be used like queries
Hopefully not any different than the way you would do it in an array. In your example below, I would have a structure for Product 1, a structure for Product 2, and so on. I would also have an ItemInYourBag structure, with the key being the product ID and the value being the quantity. If the product had more attributes, such as color or size, they would just be more members of the ItemInYourBag structure. The only list I would maintain would be the list of items in your bag, which is the same as the StructKeyList(ItemInYourBag). I don't think this helped explain why I prefer lists rather than arrays, as my solution would be structures of structures. yeah, i think that you can't do something that complex with just lists. you would have to work with arrays and/or structures. the only "problem" i can see with the structure of structures you have above has to do with what would you be using as your key for the outer structure? you would have to dynamically generate it, which seems like it would be more effort than just using the index that is inherent in an array. -emily -- Archives: http://www.eGroups.com/list/cf-talk To Unsubscribe visit http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk or send a message to [EMAIL PROTECTED] with 'unsubscribe' in the body.
