Re: Re: Storing indefinite arrays in database

Thanks Shawn, yes, your second idea works for me. The first one not, as I need to search and join on it. To continue your second idea with your example: Arguments: id results_id variable value 1 1 1 800 2 1 2 999 3 1 3 3.14 Results: id result 1 50 2 99 The Arguments and Results table would be filled dynamically by user content. In order to run a function, I have to do N times a join, whereas N is the number of arguments: select result from Results join Arguments as A1 join Arguments as A2 join Arguments as A3 on Results.id=A1.results_id and on Results.id=A2.results_id and on Results.id=A3.results_id and where A1.variable=1 and A1.value=800 and A2.variable=2 and A2.value=999 and A3.variable=3 and A3.value=3.14 and A1.results_id=Results.results_id and A2.results_id=Results.results_id and A3.results_id=Results.results_id Theoretically this works, but how good will be the performance if there are Thousands of entries? Anyway, I will try out. Thanks again, Ben Shawn McKenzie schrieb:

On 05/10/2011 03:16 PM, Benedikt Voigt wrote:

Hi, I'am very new to PHP, so please any comment is welcome. I want to write a function in PHP, which takes X arguments and outputs a value. The functioning of this function should be stored in a db (mydb? or better alternatives?) The function would look up the result in the db based on the X arguments. But how can I store X arguments and the corresponding output value? If I limit the X arguments to a specific number like N=10, then I could create N=10 +1 columns in a table. But how should I do it if I don't want to limit myself to a fix number? Thanks for any comment! Ben

Two ways that come to mind: 1. If you don't need to search, join, etc. on any of the arguments in the DB (*and never will need to*), then serialize the array and store it in one column and the result in another. 2. Use two tables: results

id          result
1           50
2           99

arguments

id          results_id          argument
1           1                   800
2           1                   999
3           1                   3.14

Then you just join results.id on arguments.results_id in your query. If you actually need to store the argument name then just add another column called variable and change the argument column's name to value.

id          results_id          variable          value

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