Обсуждение: How to use embedded sql to define an array

Hello everyone,

Can someone please tell me how to declare an array of double (float8) 
using esql  when you
don't know how long the array is until runtime?

I have the code work for a fixed length of 10, but at run-time I might only
put 2 values or there could just as easily be 100 or 200 or 5000!

I tried several variations declaring my array as a pointer, but ecpg did 
not like
any of my attempts.


Thanks,
Jeff



void    myinsert(const std::vector<double>& myVector)           {           EXEC SQL BEGIN DECLARE SECTION;

/* this would be ideal but ecpg does not like it */
/*         double          m_data[myVector.length()]; */
           /* This works but length might actually be 1 or 200! */           double          m_data[10];
           EXEC SQL END   DECLARE SECTION;
       /* stuff the sql array with data from my stl vector */       for ( unsigned int i=0; i < myVector.length(); i++
)              m_data[i] = myVector[i];
 
       EXEC SQL               insert into eraDATA                     ( data )               VALUES(  :m_data );
returnsqlOK();       }
 

On Mon, Jun 10, 2002 at 11:07:52AM -0500, Jeffrey Graham wrote:
> Can someone please tell me how to declare an array of double (float8) 
> using esql  when you
> don't know how long the array is until runtime?

How do you define the attribute in pgsql? I take it you cannot enter a
dimension here either.

>...
>        for ( unsigned int i=0; i < myVector.length(); i++ )
>                m_data[i] = myVector[i];
> 
>        EXEC SQL
>                insert into eraDATA
>                      ( data )
>                VALUES(  :m_data );
>        return sqlOK();

If you just need a way to insert the data you could write your data to a
string together with the insert command so that you end up with a
string:

insert into eraDATA ( data ) VALUES('{1,2,3,....}')

This string can be executed using EXECUTE IMMEDIATE.

Or did you mean something else?

Hope this helps.

Michael 
-- 
Michael Meskes
Michael@Fam-Meskes.De
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