[SOLVED] How to distribute a 64-bit and 32-bit version of SQLite with
my program
lazarus / 16-Databases

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Gizmo · 2017-11-14 17:04

I've read this
(http://forum.lazarus.freepascal.org/index.php?topic=35362.0) and a
few other threads
(http://forum.lazarus.freepascal.org/index.php?topic=19238.0) but up-
to-date direction still seems to be evading me.

I've re-written a program of mine to use SQLite and for the Windows
side, it's working great. I have the Windows SQLIte DLL in the same
folder as the compiled exe, and it works fine. I have the following
compiler ifdef in my code:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i {$IFDEF
Windows}       // Ensure we're using the local sqlite3.dll for
Windows       SQLiteDefaultLibrary := 'sqlite3.dll';     {$ENDIF}    
 {$IFDEF Darwin}         SQLiteDefaultLibrary := 'sqlite3-osx'; // Use
an OSX version of SQLite       {$else}         {$IFDEF UNIX and
!$ifdef Darwin}           SQLiteDefaultLibrary := 'sqlite3-linux'; //
Use a Linux version of SQLite.          {$ENDIF}     {$ENDIF}  if
FileExists(SQLiteDefaultLibrary) then     begin       // Set the
filename of the sqlite database       SQLite3Connection1.DatabaseName
:= 'DBName.sqlite';       // Create the database     
 CreateDatabase(SQLite3Connection1.DatabaseName); // THROWS ERROR
HERE       if SQLIte3Connection1.Connected then
lblConnectionStatus.Caption:= 'SQLite3 Database connection active';  
  end       else ShowMessage('Cannot create SQLite database. Ensure an
SQLite.dll or equivalent file exists'); 
So when I ran this on my Linux system last night, I got
QuoteProject raised exception class 'EInOutError' with message: Can
not load SQLite client library "sqlite-linux". Check your installation
The line that triggers that error is in another procedure where my
program creates a new SQLite database. The line
"SQLite3Connection1.Open" is what throws it, and no new database file
is created. Suggesting it can't connect to, or even create, the new
database. Yet the same code on Windows creates a new sqlite database
file.

I am running 64-bit Linux Mint 17 and Lazarus 1.6.4 and FPC 3.0.2,
installed via the deb packages for 64-bit Linux systems. The SQLite
compiled binary I am using is from http://sqlite.org/2017/sqlite-
tools-linux-x86-3210000.zip. There only seems to be one compiled
version for Linux, which I suspect may be the issue....i.e. the
version is perhaps compiled for 32-bit Linux and not 64 bit Linux, but
the fact they have only provided the one made me assume it was generic
that would work on both. 

Anyway, what I want to know is, given that most Linux distros have
SQLite installed anyway, how can I fairly reliably code my program to
look for the users copy of SQLite and then use that. Or, better still,
how can I package a 64-bit and 32-bit version of SQLite for inclusion
with my compiled binary? Or is this error related to something else
entirely!!?

Many thanks

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Gizmo · 2017-11-16 14:41

OK.

SQLiteDefaultLibrary I notice is a variable
(https://github.com/graemeg/freepascal/blob/master/packages/fcl-
db/src/sqldb/sqlite/sqlite3conn.pp). Does it somehow lookup the path
to the default sqlite program on whatever host it is running? So do I
need to specify a file at all?

Alternatively, given that SQLIte is distributed with most modern Linux
distributions anyway, what way are people using to lookup the SQLIte
path for the distro in which their program finds itself running? How
do the likes of Firefox and Chrome achieve this. Both of which use
SQLIte massively.

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molly · 2017-11-16 15:53

hi Gizmo,

Perhaps this wiki-page and this thread might be able to help you out a
bit.

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mig-31 · 2017-11-16 16:11

It's simple.
There is POSIX standard = sqlite.so must be is in /usr/lib 32-bit and
/usr/lib64

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molly · 2017-11-16 16:27

In addition to mig-31's answer have a look at this wiki article.

That's why i mentioned TSQLDBLibraryLoader, e.g. for those cases that
you disagree with (or for whatever reason, can't use) the order as
described.

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Gizmo · 2017-11-20 22:11

Thanks guys.

So, to simply bundle and use pre-compiled binaries that I ship with
the exe, would this work and be sensible or a bad idea?

Code: [Select]  SQLDBLibraryLoader1.ConnectionType:='SQLite3';
  {$ifdef windows}
    SQLDBLibraryLoader1.LibraryName := 'sqlite-win.dll';
{$else}
  {$ifdef darwin}
     SQLDBLibraryLoader1.LibraryName := 'sqlite-osx';
  {$else}
    SQLDBLibraryLoader1.LibraryName := 'sqlite-linux';
  {$endif}
{$endif}
  SQLDBLibraryLoader1.Enabled := true;
  SQLDBLibraryLoader1.LoadLibrary;

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molly · 2017-11-20 23:58

@Gizmo:
afaik the safest way would be to use full path names, since you are
shipping your own you also know where they are located exactly. You
could even opt for a config file that allows to override your 'static'
used defaults.

PS: if i remember correctly then the loadlibrary method is called
automatically when enabled is set to true (even though the wiki calls
this method explicitly in the example).

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Gizmo · 2017-11-21 23:30

Thank you Molly, for the tip re SQLDBLibraryLoader. Using three
instances of that for each OS (to save a single one being adjusted
when compiled on different platforms), I've created a working cross
platform system that can utilise SQLite, without any fellow coders
having to reconfigure the SQLDBLibraryLoader object .

Try as I might, I couldn't get local downloaded pre-compiled versions
to work with Linux and OSX. So by querying the default paths on both
platforms, and given that both pretty much all (at least most) modern
Linux distros and OSX versions come with SQLite, the code below should
work for most users I hope. It works on all three of my systems
anyway. For Windows users, I ship the DLL.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i {$ifdef
windows}    SQLDBLibraryLoaderWindows.ConnectionType:='SQLite3';    if
FileExists('sqlite3-win.dll') then    begin     
SQLDBLibraryLoaderWindows.LibraryName := 'sqlite3-win.dll';     
SQLDBLibraryLoaderWindows.Enabled := true;     
SQLDBLibraryLoaderWindows.LoadLibrary;      // Set the filename of the
sqlite database      SQLite3Connection1.DatabaseName :=
'QuickHashDBWin.sqlite';      // Create the database     
CreateDatabase(SQLite3Connection1.DatabaseName);      if
SQLIte3Connection1.Connected then lblConnectionStatus.Caption:=
'SQLite3 Database connection active';    end    else    begin     
ShowMessage('Cannot create SQLite database. Ensure you extracted the
sqlite-win.dll file from the zip file');      exit;    end;  {$else} 
 {$ifdef darwin}    SQLDBLibraryLoaderOSX.ConnectionType:='SQLite3'; 
 // OSX sqlite file is a dynamic lib libsqlite3.dylib     if
FileExists('/usr/lib/libsqlite3.dylib') then    begin     
SQLDBLibraryLoaderOSX.LibraryName := '/usr/lib/libsqlite3.dylib';    
SQLDBLibraryLoaderOSX.Enabled := true;     
SQLDBLibraryLoaderOSX.LoadLibrary;      // Set the filename of the
sqlite database      SQLite3Connection1.DatabaseName :=
'QuickHashDBOSX.sqlite';      // Create the database     
CreateDatabase(SQLite3Connection1.DatabaseName);      if
SQLIte3Connection1.Connected then lblConnectionStatus.Caption:=
'SQLite3 Database connection active';    end    else    begin     
ShowMessage('Cannot create SQLite database. Is SQLite installed?');  
  exit;    end;    {$else}     // If it's 64-bit Linux, use the 64-bit
SQLite3 install    if FileExists('/usr/lib/x86_64-linux-
gnu/libsqlite3.so.0') then      begin       
SQLDBLibraryLoaderLinux.LibraryName := '/usr/lib/x86_64-linux-
gnu/libsqlite3.so.0';        SQLDBLibraryLoaderLinux.Enabled := true; 
      SQLDBLibraryLoaderLinux.LoadLibrary;        // Set the filename
of the sqlite database       SQLite3Connection1.DatabaseName :=
'QuickHashDBLinux.sqlite';       // Create the database     
 CreateDatabase(SQLite3Connection1.DatabaseName);       if
SQLIte3Connection1.Connected then lblConnectionStatus.Caption:=
'SQLite3 Database connection active';      end    // If it's 32-bit
Linux, use the 32-bit SQLite3 install      else if
FileExists('/usr/lib/i386-linux-gnu/libsqlite3.so.0') then       
begin          SQLDBLibraryLoaderLinux.LibraryName :=
'/usr/lib/i386-linux-gnu/libsqlite3.so.0';         
SQLDBLibraryLoaderLinux.Enabled := true;         
SQLDBLibraryLoaderLinux.LoadLibrary;          // Set the filename of
the sqlite database         SQLite3Connection1.DatabaseName :=
'QuickHashDBLinux.sqlite';         // Create the database       
 CreateDatabase(SQLite3Connection1.DatabaseName);         if
SQLIte3Connection1.Connected then lblConnectionStatus.Caption:=
'SQLite3 Database connection active';        end    else    begin    
ShowMessage('Cannot create SQLite database. Ensure SQLite3 is
installed in your Linux distribution');      exit;    end;   
{$endif}{$endif}