Hi, > How to store multiple values in a single field? Is there any array data > type > concept in mysql? > As Jörg said "Multiple values in a single field" would be an explicit violation of the relational model..."
then also, if you want to use. this might be this will help you. I used like this in past: In database, I have taken a column as TEXT. In which I have separated a value by *- *(hifen) eg. furniture table there is 2 col , name (person name) - used (furniture's used by that person). value will be : > ==================== > | Name | Used | > -------------------------------------- > | Prabhat | chair-table-bed | > =================== > And in PHP you can easily separate these value. eg, > $names = "Markus;Nigel;David"; > To use these names in a meaningful way, we should first separate them into an array ($namearray), using explode()<http://au3.php.net/manual/en/function.explode.php> : $namearray = explode(";", $names); The end result: $namearray = Array ( [0] => Markus [1] => Nigel [2] => David ) But remember this is VERY bad database design. I had used since, that was required for few days only. Thanks, In database : On Sun, May 16, 2010 at 9:34 PM, Mark Goodge <m...@good-stuff.co.uk> wrote: > On 14/05/2010 09:54, Joerg Bruehe wrote: > >> Hi Samrat, all! >> >> >> Samrat Kar wrote: >> >>> Hello, >>> >>> >>> >>> How to store multiple values in a single field? Is there any array data >>> type >>> concept in mysql? >>> >> >> "Multiple values in a single field" would be an explicit violation of >> the relational model (on which the SQL language is based) and cause all >> kinds of trouble in your queries. >> >> Ever and again, developers use some kind of encoding to store a >> combination of values (like flags in a bit field) in one database field, >> but in many cases this makes queries very hard to write, and may prevent >> optimization of the SQL statement. >> >> It depends on your application, especially on whether this field will be >> used in search conditions ("... WHERE combined_field has flag_X ..."), >> to decide about a sensible approach. >> In general, I would prefer separate fields for different flags, and a >> separate table for a truly multi-valued field (like multiple postal or >> mail addresses for a person). >> > > If you're merely *storing* the data in the table, and will only ever > retrieve it based on other factors - that is, you'll never use that field > for any operands including joins and 'where' clauses - then it's often > useful to store a flattened array (eg, one created by PHP's serialize() > function, javascript JSON or even XML) as a string and then expand it to an > array again after retrieving it. That can often be a useful way of storing > meta-data about a data object (eg, EXIF data from a photograph), especially > where you can't know in advance what the array structure will be when you > create the database. > > However, that's not really an array datatype in MySQL, it's simply a method > of storing an array as a string. So it's of fairly limited application, > there are cases where it's very useful but it's not a substitute for storing > the array values separately using the appropriate table design where you do > need to run queries against it. > > Mark > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: > http://lists.mysql.com/mysql?unsub=aim.prab...@gmail.com > > -- Best Regards, Prabhat Kumar MySQL DBA Datavail-India Mumbai Mobile : 91-9987681929 www.datavail.com My Blog: http://adminlinux.blogspot.com My LinkedIn: http://www.linkedin.com/in/profileprabhat
