I've been working to attempt to get DDBI to work with MySQL. Unfortunately I'm stuck with the Windows platform for lack of the impetus and know-how to get the compiler working elsewhere.

I use a slightly modified version of DDBI to get SQLite to work.  I don't think that would disrupt the workings of MySQL.

Once I found the correct library file to use (buried in a large download of MySQL - the server, which was annoying) I found that the whole she-bang didn't work at all.  It was all tied to a strange external declaration in imp_win.d, which apparently decided that on Windows the MySQL support is provided by extern(Windows) instead of extern(C).

Once I got that cleared up, I started a bunch of "cannot implicitly cast foo* to foo*" errors, which mystified me.  I think it's because one is tossing an alias of something to something that's expecting the un-aliased something, and so it's having some issues.

So attempting to fix the issues didn't work terribly well.  I beat through a few pointer issues to get hung up on a weird pointer issue which emits this error:

dbi\mysql\MysqlDatabase.d(194): constructor
dbi.mysql.MysqlResult.MysqlResult.th
is (st_mysql_res*) does not match parameter types (st_mysql_res*)
dbi\mysql\MysqlDatabase.d(194): Error: cannot implicitly convert
expression (cas
t(st_mysql_res*)*results) of type st_mysql_res* to st_mysql_res*

I'm pretty puzzled.  I've tried casting it explicitly, and it doesn't work.  I'd really appreciate it if someone knew what is going on.  When I explicitly cast it, it still give the same error.

This is DMD version 1.033.

Chris R. Miller wrote:
> I've been working to attempt to get DDBI to work with MySQL.
> Unfortunately I'm stuck with the Windows platform for lack of the
> impetus and know-how to get the compiler working elsewhere.
> 
> I use a slightly modified version of DDBI to get SQLite to work.  I
> don't think that would disrupt the workings of MySQL.
> 
> Once I found the correct library file to use (buried in a large download
> of MySQL - the server, which was annoying) I found that the whole
> she-bang didn't work at all.  It was all tied to a strange external
> declaration in imp_win.d, which apparently decided that on Windows the
> MySQL support is provided by extern(Windows) instead of extern(C).

I hope you changed that to extern(System) ? It sounds like an old MySQL file.

> 
> Once I got that cleared up, I started a bunch of "cannot implicitly cast
> foo* to foo*" errors, which mystified me.  I think it's because one is
> tossing an alias of something to something that's expecting the
> un-aliased something, and so it's having some issues.
> 
> So attempting to fix the issues didn't work terribly well.  I beat
> through a few pointer issues to get hung up on a weird pointer issue
> which emits this error:
> 
> dbi\mysql\MysqlDatabase.d(194): constructor
> dbi.mysql.MysqlResult.MysqlResult.th
> is (st_mysql_res*) does not match parameter types (st_mysql_res*)
> dbi\mysql\MysqlDatabase.d(194): Error: cannot implicitly convert
> expression (cas
> t(st_mysql_res*)*results) of type st_mysql_res* to st_mysql_res*
> 
> I'm pretty puzzled.  I've tried casting it explicitly, and it doesn't
> work.  I'd really appreciate it if someone knew what is going on.  When
> I explicitly cast it, it still give the same error.
> 
> This is DMD version 1.033.
> 

Don wrote:
> Chris R. Miller wrote:
>> I've been working to attempt to get DDBI to work with MySQL. Unfortunately I'm stuck with the Windows platform for lack of the impetus and know-how to get the compiler working elsewhere.
>>
>> I use a slightly modified version of DDBI to get SQLite to work.  I don't think that would disrupt the workings of MySQL.
>>
>> Once I found the correct library file to use (buried in a large download of MySQL - the server, which was annoying) I found that the whole she-bang didn't work at all.  It was all tied to a strange external declaration in imp_win.d, which apparently decided that on Windows the MySQL support is provided by extern(Windows) instead of extern(C).
> 
> I hope you changed that to extern(System) ? It sounds like an old MySQL
> file.

No, it all links properly with extern(C).

On Fri, 29 Aug 2008 01:07:35 -0700, "Chris R. Miller" <lordSaurontheGreat@gmail.com> wrote:

>Don wrote:
>> Chris R. Miller wrote:
>>> I've been working to attempt to get DDBI to work with MySQL. Unfortunately I'm stuck with the Windows platform for lack of the impetus and know-how to get the compiler working elsewhere.
>>>
>>> I use a slightly modified version of DDBI to get SQLite to work.  I don't think that would disrupt the workings of MySQL.
>>>
>>> Once I found the correct library file to use (buried in a large download of MySQL - the server, which was annoying) I found that the whole she-bang didn't work at all.  It was all tied to a strange external declaration in imp_win.d, which apparently decided that on Windows the MySQL support is provided by extern(Windows) instead of extern(C).
>> 
>> I hope you changed that to extern(System) ? It sounds like an old MySQL
>> file.
>
>No, it all links properly with extern(C).
>

MySQL API uses stdcall calling convention on Windows so extern(Windows) in imp_win.d is correct. Here is an import library for libmysql.dll that works for me http://d-coding.com/downloads/libmysql.lib

On 2008-08-29 09:47:30 +0200, "Chris R. Miller" <lordSaurontheGreat@gmail.com> said:

> [...]
> Once I got that cleared up, I started a bunch of "cannot implicitly cast
> foo* to foo*" errors, which mystified me.  I think it's because one is
> tossing an alias of something to something that's expecting the
> un-aliased something, and so it's having some issues.
> 
> So attempting to fix the issues didn't work terribly well.  I beat
> through a few pointer issues to get hung up on a weird pointer issue
> which emits this error:
> 
> dbi\mysql\MysqlDatabase.d(194): constructor
> dbi.mysql.MysqlResult.MysqlResult.th
> is (st_mysql_res*) does not match parameter types (st_mysql_res*)
> dbi\mysql\MysqlDatabase.d(194): Error: cannot implicitly convert
> expression (cas
> t(st_mysql_res*)*results) of type st_mysql_res* to st_mysql_res*
> 
> I'm pretty puzzled.  I've tried casting it explicitly, and it doesn't
> work.  I'd really appreciate it if someone knew what is going on.  When
> I explicitly cast it, it still give the same error.

I had a similar error today in my template code with int* and int* (I think also connected with aliases and nesting of templates).
I haven't distilled it yet, but using

	cast(T*)(cast(size_t)a+cast(size_t)b)

in my case fixed the issue...

Fawzi

Fawzi Mohamed wrote:
> On 2008-08-29 09:47:30 +0200, "Chris R. Miller" <lordSaurontheGreat@gmail.com> said:
> 
>> [...]
>> Once I got that cleared up, I started a bunch of "cannot implicitly cast
>> foo* to foo*" errors, which mystified me.  I think it's because one is
>> tossing an alias of something to something that's expecting the
>> un-aliased something, and so it's having some issues.
>>
>> So attempting to fix the issues didn't work terribly well.  I beat through a few pointer issues to get hung up on a weird pointer issue which emits this error:
>>
>> dbi\mysql\MysqlDatabase.d(194): constructor
>> dbi.mysql.MysqlResult.MysqlResult.th
>> is (st_mysql_res*) does not match parameter types (st_mysql_res*)
>> dbi\mysql\MysqlDatabase.d(194): Error: cannot implicitly convert
>> expression (cas
>> t(st_mysql_res*)*results) of type st_mysql_res* to st_mysql_res*
>>
>> I'm pretty puzzled.  I've tried casting it explicitly, and it doesn't work.  I'd really appreciate it if someone knew what is going on.  When I explicitly cast it, it still give the same error.
> 
> I had a similar error today in my template code with int* and int* (I
> think also connected with aliases and nesting of templates).
> I haven't distilled it yet, but using
> 
>     cast(T*)(cast(size_t)a+cast(size_t)b)
> 
> in my case fixed the issue...
> 
> Fawzi

Glad it worked for you!  I wasn't so lucky.

Max Samukha wrote:
> On Fri, 29 Aug 2008 01:07:35 -0700, "Chris R. Miller" <lordSaurontheGreat@gmail.com> wrote:
> 
>> Don wrote:
>>> Chris R. Miller wrote:
>>>> I've been working to attempt to get DDBI to work with MySQL. Unfortunately I'm stuck with the Windows platform for lack of the impetus and know-how to get the compiler working elsewhere.
>>>>
>>>> I use a slightly modified version of DDBI to get SQLite to work.  I don't think that would disrupt the workings of MySQL.
>>>>
>>>> Once I found the correct library file to use (buried in a large download of MySQL - the server, which was annoying) I found that the whole she-bang didn't work at all.  It was all tied to a strange external declaration in imp_win.d, which apparently decided that on Windows the MySQL support is provided by extern(Windows) instead of extern(C).
>>> I hope you changed that to extern(System) ? It sounds like an old MySQL
>>> file.
>> No, it all links properly with extern(C).
>>
> 
> MySQL API uses stdcall calling convention on Windows so extern(Windows) in imp_win.d is correct. Here is an import library for libmysql.dll that works for me http://d-coding.com/downloads/libmysql.lib

Changed it back to extern(Windows) and still no joy.  I also tried using your supplied library file, but nothing worked, either.

As soon as I changed it from extern(C) I was greeted by these errors though:

dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
 Error 42: Symbol Undefined _mysql_init@4
dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
 Error 42: Symbol Undefined _mysql_real_connect@32
dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
 Error 42: Symbol Undefined _mysql_errno@4
dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
 Error 42: Symbol Undefined _mysql_error@4
dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
 Error 42: Symbol Undefined
_D3dbi5mysql10MysqlError17specificToGeneralFkZE3dbi9
ErrorCode9ErrorCode
dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
 Error 42: Symbol Undefined _mysql_close@4
dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
 Error 42: Symbol Undefined _mysql_real_query@12
dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
 Error 42: Symbol Undefined _mysql_store_result@4
dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
 Error 42: Symbol Undefined _mysql_insert_id@4
dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
 Error 42: Symbol Undefined _mysql_get_client_version@0
dsss_objs\D\dbi-mysql-MysqlResult.obj(dbi-mysql-MysqlResult)
 Error 42: Symbol Undefined _mysql_fetch_row@4
dsss_objs\D\dbi-mysql-MysqlResult.obj(dbi-mysql-MysqlResult)
 Error 42: Symbol Undefined _mysql_fetch_lengths@4
dsss_objs\D\dbi-mysql-MysqlResult.obj(dbi-mysql-MysqlResult)
 Error 42: Symbol Undefined _mysql_free_result@4
dsss_objs\D\dbi-mysql-MysqlResult.obj(dbi-mysql-MysqlResult)
 Error 42: Symbol Undefined _mysql_num_fields@4
dsss_objs\D\dbi-mysql-MysqlResult.obj(dbi-mysql-MysqlResult)
 Error 42: Symbol Undefined _mysql_fetch_fields@4

I'm not an expert at all, but I think that's because it can't discover
the functions to link against.  If I change it back to extern(C) I get this:

dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
 Error 42: Symbol Undefined
_D3dbi5mysql10MysqlError17specificToGeneralFkZE3dbi9
ErrorCode9ErrorCode

Which is a regression from what I had when I had changed it to ignore imp_win.d and to use imp.d instead.

So I'm thoroughly confused.  I suspect that I *almost* had it working with the imp.d save for the cast problems (which could be a compiler bug - if it's not, then there's a lot I'm going to be learning about pointers in my upcoming CS 102 class!)

On Fri, 29 Aug 2008 20:16:22 -0700, "Chris R. Miller" <lordSaurontheGreat@gmail.com> wrote:

>dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
> Error 42: Symbol Undefined _mysql_init@4
>dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
> Error 42: Symbol Undefined _mysql_real_connect@32
>dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
> Error 42: Symbol Undefined _mysql_errno@4
>dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
> Error 42: Symbol Undefined _mysql_error@4
>dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
> Error 42: Symbol Undefined
>_D3dbi5mysql10MysqlError17specificToGeneralFkZE3dbi9 ErrorCode9ErrorCode dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
> Error 42: Symbol Undefined _mysql_close@4
>dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
> Error 42: Symbol Undefined _mysql_real_query@12
>dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
> Error 42: Symbol Undefined _mysql_store_result@4
>dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
> Error 42: Symbol Undefined _mysql_insert_id@4
>dsss_objs\D\dbi-mysql-MysqlDatabase.obj(dbi-mysql-MysqlDatabase)
> Error 42: Symbol Undefined _mysql_get_client_version@0
>dsss_objs\D\dbi-mysql-MysqlResult.obj(dbi-mysql-MysqlResult)
> Error 42: Symbol Undefined _mysql_fetch_row@4
>dsss_objs\D\dbi-mysql-MysqlResult.obj(dbi-mysql-MysqlResult)
> Error 42: Symbol Undefined _mysql_fetch_lengths@4
>dsss_objs\D\dbi-mysql-MysqlResult.obj(dbi-mysql-MysqlResult)
> Error 42: Symbol Undefined _mysql_free_result@4
>dsss_objs\D\dbi-mysql-MysqlResult.obj(dbi-mysql-MysqlResult)
> Error 42: Symbol Undefined _mysql_num_fields@4
>dsss_objs\D\dbi-mysql-MysqlResult.obj(dbi-mysql-MysqlResult)
> Error 42: Symbol Undefined _mysql_fetch_fields@4
>
All those symbols are exported by the lib I supplied. I guess you are still trying to link against a wrong lib. Check your lib paths.


>I'm not an expert at all, but I think that's because it can't discover
>the functions to link against.  If I change it back to extern(C) I get this:
>

Even if you manage to link using extern(C), your program won't work
correctly, because C and Windows calling conventions differ not only
in name decorations. So you must use either extern(Windows) or
extern(System).