Code Optimization, PostgreSQL BLOBs (Cheat Method)

[Jan Schenkel]

--- "Frank D. Engel, Jr." <fde101 at fjrhome.net> wrote:
> After some research and "playing," I've *finally*
> found a way to get 
> info into and out of PostgreSQL BYTEA BLOBs through
> RevDB, but it is 
> painfully slow.  I wrote the following functions:
> 
> function dbBLOB bdat
>    put "'" into x
>    repeat for each char c in bdat
>      put format("\\\\%03o", charToNum(c)) after x
>    end repeat
> 
>    return x & "'::bytea"
> end dbBLOB
> 
> function dbUNBLOB adat
>    put empty into x
>    put 0 into y
>    put 0 into n
>    put false into esc
>    repeat for each char c in adat
>      if esc then
>        if c is "\" then
>          put "\" after x
>          put false into esc
>        else
>          put (8 * y) + c into y
>          add 1 to n
>          if n is 3 then
>            put numToChar(y) after x
>            put 0 into y
>            put 0 into n
>            put false into esc
>          end if
>        end if
>      else if c is "\" then put true into esc
>      else put c after x
>    end repeat
> 
>    return x
> end dbUNBLOB
> 
> 
> dbBLOB encodes binary data stored in strings (such
> as the text property 
> of an image) into a BYTEA literal which can be used
> in an INSERT or 
> UPDATE statement:
> 
> on mouseUp
>    revExecuteSQL the database of this stack, "INSERT
> INTO table1 VALUES 
> (" & dbBLOB(image "Image 1") & ")"
> end mouseUp
> 
> 
> dbUNBLOB decodes binary data returned from the
> server back into a 
> string:
> 
> on mouseUp
>    put revQueryDatabase(the database of this stack,
> "SELECT * FROM 
> table1") into q
>    if q is an integer then
>      if revNumberOfRecords(q) > 0 then
>        put dbUNBLOB(revDatabaseColumnNumbered(q, 1))
> into image "Image 1"
>      else answer "No Records"
>      revCloseCursor q
>    else answer q titled "Error"
> end mouseUp
> 
> 
> Perhaps the functions will help someone else in a
> similar situation; 
> also, if anyone can find a way to speed these up, I
> would certainly 
> appreciate it...
> 
> Frank D. Engel, Jr.

Hi Frank,

If no other applications needs to access the data, you
could just store a Base64 copy of the image data in a
field of type text.

A bit late now, I know...

Jan Schenkel.

=====
"As we grow older, we grow both wiser and more foolish at the same time."  (La Rochefoucauld)


		
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