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Author Topic: SQLITE3.DLL  (Read 591 times)

TonyR500

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SQLITE3.DLL
« on: July 06, 2020, 02:36:49 pm »
Hi
Some years ago I wrote some Delphi applications for a company in the midlands and recently I was asked to do some enhancements to these Delphi programs.

Since modern versions of Delphi appear to be very expensive I decided to try to use Lazarus.
Although it seems very similar to Delphi I am a newcomer to Lazarus.

I have now downloaded the 64 bit version of Lazarus and am using this with Windows 7 (not yet updated to Windows 10). I am currently trying to rewrite the 'Contacts' application used in the Sales Office. This is a simple application currently using dBase DBF files.

I have decided to replace these with a SQLite3 database. When I try to activate the SQLQuery component on my form I get an error message.

"Cannot load SQLite client library sqlite3.dll. Check your installation".

Also on the form are a SQLite3Connection, a SQLTransaction and a datasource component all connected in the usual way. There is also a DBGrid and a DBNavigator 

I have sqlite3.dll in my project folder and the Lazarus installation is brand new. Should I reinstall Lazarus or do I have sqlite3.dll in the wrong place.

Very glad of any suggestions.

Many Thanks
AJR

Awkward

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Re: SQLITE3.DLL
« Reply #1 on: July 06, 2020, 03:28:02 pm »
check first what your program and SQLite3.dll have the same bitness. i mean, app and dll can be x86 or x64. check whatthey are the same.

PascalDragon

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Re: SQLITE3.DLL
« Reply #2 on: July 06, 2020, 04:18:43 pm »
I have decided to replace these with a SQLite3 database. When I try to activate the SQLQuery component on my form I get an error message.

"Cannot load SQLite client library sqlite3.dll. Check your installation".

Also on the form are a SQLite3Connection, a SQLTransaction and a datasource component all connected in the usual way. There is also a DBGrid and a DBNavigator 

I have sqlite3.dll in my project folder and the Lazarus installation is brand new. Should I reinstall Lazarus or do I have sqlite3.dll in the wrong place.

To use SQLite from within the IDE (not your application) you need to place the library next to the Lazarus executable. The same is true for other DB clients that require a client DLL if they don't provide a global installation.

jamie

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Re: SQLITE3.DLL
« Reply #3 on: July 06, 2020, 04:19:39 pm »
you may need to down load and install the DLL file..

https://www.sqlite.org/download.html


Scroll down and pick the precompiled binaries and select the target you need.

 you could first try putting this DLL into your project folder
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TonyR500

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Re: SQLITE3.DLL
« Reply #4 on: July 06, 2020, 11:43:15 pm »
Hi

Thanks v much for all help. I downloaded sqlite3.dll from sqlite.org making sure I have the correct version. I then put this into the Lazarus executable folder. Result success. I now found I could make the SQLQuery component active without getting an error message.

I have since found that I also need sqlite3.dll in the same folder as the project executable. Without it  there are error messages at runtime. Problem therefore appears to be solved.

Many thanks again to all for help.

AJR

PascalDragon

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Re: SQLITE3.DLL
« Reply #5 on: July 07, 2020, 09:37:23 am »
I have since found that I also need sqlite3.dll in the same folder as the project executable. Without it  there are error messages at runtime. Problem therefore appears to be solved.

Yes, it needs to be in both locations as both binaries (the lazarus.exe and your application) need to be able to load the library.

Zvoni

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Re: SQLITE3.DLL
« Reply #6 on: July 07, 2020, 10:31:40 am »
On a sidenote:
IIRC, for Windows, the "recommended" Lazarus-Version is 32-Bit, and then to cross-compile to x64
But might be wrong.
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Pascal

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Re: SQLITE3.DLL
« Reply #7 on: July 07, 2020, 10:57:02 am »
I have since found that I also need sqlite3.dll in the same folder as the project executable. Without it  there are error messages at runtime. Problem therefore appears to be solved.

Yes, it needs to be in both locations as both binaries (the lazarus.exe and your application) need to be able to load the library.

On a 64 bit Windows you can also put both dlls in the systems default locations:

64 bit dll to: C:\Windows\system32
32 bit dll to: C:\Windows\SysWOW64

So both 32 and 64 bit apps will work without copying dlls to the executable directories.
laz trunk - fpc trunk 32bit - Windows 10 Pro x64 (1909)

Awkward

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Re: SQLITE3.DLL
« Reply #8 on: July 07, 2020, 11:05:56 am »
On a 64 bit Windows you can also put both dlls in the systems default locations:

64 bit dll to: C:\Windows\system32
32 bit dll to: C:\Windows\SysWOW64

So both 32 and 64 bit apps will work without copying dlls to the executable directories.

But that slightly dangerous coz if you publishing your program, you have a chance to forget to distribute sqlite3.dll with it

PascalDragon

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Re: SQLITE3.DLL
« Reply #9 on: July 07, 2020, 01:02:49 pm »
On a 64 bit Windows you can also put both dlls in the systems default locations:

64 bit dll to: C:\Windows\system32
32 bit dll to: C:\Windows\SysWOW64

So both 32 and 64 bit apps will work without copying dlls to the executable directories.

Yes, global directories are possible, but this has the danger - aside from what Awkward mentioned - that the global library might have an incompatible version. And Windows DLL usually are not versioned unlike *nix ones.

Pascal

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Re: SQLITE3.DLL
« Reply #10 on: July 07, 2020, 01:33:37 pm »
Yes, global directories are possible, but this has the danger - aside from what Awkward mentioned - that the global library might have an incompatible version. And Windows DLL usually are not versioned unlike *nix ones.

Okay, convinced  :)
laz trunk - fpc trunk 32bit - Windows 10 Pro x64 (1909)

 

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