REGEX in SQLite

[jchd]

Ticket #2778 is asking for an implementation. I don't believe there is a common need for inclusion of such feature in the standard delivery.

I compiled the regex.c source from the official SQLite 3.8.5 distribution and tested it. It works decently well but don't expect it to be fast compared to built-in possibilities. Please refer to the official source where you'll find details about supported pattern elements.

For those who want to try it, you can download a 32-bit extension DLL. It has been compiled with x86 tcc so it's not highly optimized (which doesn't matter much in this case). You'll find >in this post support to manage SQLite extensions.

EDIT: Dropbox once again decided to kill old links. Files are there:

sqlite3-pcre.zip sqlite3-pcre-src.zip

Edited August 6, 2020 by jchd
Solve dead D/L link

[Andreik]

Thanks for sharing. I made an example script:

#include <SQLite.au3>
#include <SQLite.dll.au3>
#include <SQLiteExtLoad.au3>

Local $aResult, $iRows, $iColumns

_SQLite_Startup()
$hDB = _SQLite_Open()
_SQLite_EnableExtensions($hDB,1)
_SQLite_LoadExtension($hDB,@ScriptDir & '\regexp.dll','sqlite3_regexp_init')
_SQLite_Exec($hDB,"CREATE TABLE Example(ID int,Data varchar(50))")
For $Index = 1 To 2000
    _SQLite_Exec($hDB,"INSERT INTO Example(ID,Data) VALUES(" & $Index & "," & _SQLite_FastEscape(RandomChars()) & ")")
Next
_SQLite_GetTable2d($hDB,"SELECT ID,Data FROM Example WHERE Data REGEXP '^\d{3}'",$aResult,$iRows,$iColumns)
_SQLite_Display2DResult($aResult)
_SQLite_Close($hDB)

Func RandomChars()
    Local $sChars
    Local $aCharset = StringSplit('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789','')
    For $Index = 1 To 50
        $sChars &= $aCharset[Random(1,$aCharset[0],1)]
    Next
    Return $sChars
EndFunc

[jchd]

Fine, thanks.

[asparagus]

On 7/28/2014 at 1:23 AM, Andreik said:

Thanks for sharing. I made an example script:

Hi,  Andreik

 

Would you Please show me where can I download the regexp.dll ?

Much Thanks

[asparagus]

On 7/28/2014 at 1:34 AM, jchd said:

Fine, thanks.

Hi, Jchd

the link  https://dl.dropboxusercontent.com/u/26433628/SQLite Extensions/regexp.dll

is broken , would you please offer a valid one ?

much thanks

[jchd]

Easy. Here's the X86 .dll and the source file:

sqlite3-pcre.zip

sqlite3-pcre-src.zip

The regex engine used is PCRE v1, the same as AutoIt currently uses.

Edited December 31, 2022 by jchd

[asparagus]

Hi, jchd , Much Thanks

[jchd]

BTW these files are the same as in post #1 of this very same thread.

[asparagus]

On 1/1/2023 at 2:37 AM, jchd said:

Easy. Here's the X86 .dll and the source file:

sqlite3-pcre.zip 81.17 kB · 18 downloads

sqlite3-pcre-src.zip 329.38 kB · 18 downloads

The regex engine used is PCRE v1, the same as AutoIt currently uses.

Yes , I had downloaded it previously. but  it threw an error when I run Andreik's  scirpt  such as below:

!   SQLite.au3 Error
--> Function: _SQLite_Query
--> Query:    SELECT ID,Data FROM Example WHERE Data REGEXP '^\d{3}'
--> Error:    no such function: REGEXP

And of course , Error still occurs when I re-download these files you offer and rename the file to regexp.dll within sqlite3-pcre.zip

Would you please tell me what's wrong with it ?

Much Tanks

[jchd]

Post a _short_ & self-contained reproducer script.

Edited January 7, 2023 by jchd

[jchd]

Sorry, I didn't look at the example code dated 2014!

This code was for the first version of the DLL, which used the minimal regex engine available in the SQLite source tree.

My version uses a differently named init function. So change the code to:

_SQLite_LoadExtension($hDB,@ScriptDir & '\sqlite3-pcre.dll','sqlite3_extension_init')

Of course, adapt DLL name and location.