Recreating array from SQL field

[José Luis Ramírez]

Hi,

I'm trying to recreate an array from a var_export()'ed array stored in
a database, using eval().

Basically I have something this in my database:

array (
0 => 1,
1 => 2,
2 => array (
0 => 'a',
1 => 'b',
2 => 'c',
),
)


If I then read it into a variable:

$stored_array = /*whatever_sql_s tatements_for_r eading_stored_a rray*/

I would think that something like:

eval('$recreate d_array = $store_array');

would do, but it sjust doesn't work, and I'm quite stumped with this
simple task, but I'd appreciate anyone' guidance.

Cheers!

- José

p.s. The solution would be be a welcome addition to the PHP
documentation since there is only a hint of how one could do this but
not a working example.

[Michael Fesser]

Re: Recreating array from SQL field

.oO(José Luis Ramírez)
[color=blue]
>I'm trying to recreate an array from a var_export()'ed array stored in
>a database, using eval().[/color]

eval() is slow. What about serialize()/unserialize()?
[color=blue]
>I would think that something like:
>
>eval('$recreat ed_array = $store_array');
>
>would do, but it sjust doesn't work, and I'm quite stumped with this
>simple task, but I'd appreciate anyone' guidance.[/color]

eval("\$recreat ed_array = $store_array;") ;
[color=blue]
>p.s. The solution would be be a welcome addition to the PHP
>documentatio n since there is only a hint of how one could do this but
>not a working example.[/color]

There are working examples for eval() in the manual.

Micha

[José Luis Ramírez]

Re: Recreating array from SQL field

Michael Fesser wrote:[color=blue]
> .oO(José Luis Ramírez)
>[color=green]
> >I'm trying to recreate an array from a var_export()'ed array stored[/color][/color]
in[color=blue][color=green]
> >a database, using eval().[/color]
>
> eval() is slow. What about serialize()/unserialize()?
>[/color]

Yes. I had already done some tests with serialize()/unserialize(). But
was derailed after finding var_export().

I'm going back to serialize()/unserialize(). Thanks.

[color=blue][color=green]
> >I would think that something like:
> >
> >eval('$recreat ed_array = $store_array');
> >
> >would do, but it sjust doesn't work, and I'm quite stumped with this
> >simple task, but I'd appreciate anyone' guidance.[/color]
>
> eval("\$recreat ed_array = $store_array;") ;[/color]



So the only difference was the missing semi-colon? I'm testing it right
now.

[color=blue][color=green]
> >p.s. The solution would be be a welcome addition to the PHP
> >documentatio n since there is only a hint of how one could do this[/color][/color]
but[color=blue][color=green]
> >not a working example.[/color]
>
> There are working examples for eval() in the manual.
>
> Micha[/color]

I suppose I didn't make myself clear. There ARE a lot of examples on
the eval() page, but not any that tell you explicitly how to recreate a
var_export()'ed array, at least since I checked yesterday, I could be
wrong, maybe I missed the example. Anyway, thanks!

J.L.

[Michael Fesser]

Re: Recreating array from SQL field

.oO(José Luis Ramírez)
[color=blue]
>Michael Fesser wrote:
>[color=green]
>> eval("\$recreat ed_array = $store_array;") ;[/color]
>
>So the only difference was the missing semi-colon?[/color]

Not exactly. Compare the two:

eval('$recreate d_array = $store_array');
eval("\$recreat ed_array = $store_array;") ;

Differences in the second:

* double quotes around the string, so embedded variables will be
replaced by their values
* an escaped $ on the first variable, this means it will be passed as-is
to eval(), only $store_array will be replaced by its value
* the missing semicolon

This is the string eval() will finally get and execute:

$recreated_arra y = array(... stuff from db here ...);
[color=blue]
>I suppose I didn't make myself clear. There ARE a lot of examples on
>the eval() page, but not any that tell you explicitly how to recreate a
>var_export()'e d array, at least since I checked yesterday, I could be
>wrong, maybe I missed the example. Anyway, thanks![/color]

There is an (bad, but working) example of how to assign a value to a
variable with eval(). It doesn't matter if it's a scalar or an array,
the syntax is the same. You only have to know when it's necessary to
escape a $ and when not.

Micha