Thread: C API for MySQL

Help me please,

I am having a problem getting the C API to work with in C. I have tried it with DevC++ as a C program, I have tried it in DJGPP, I have tried it in MingW. First off, to my understanding, C library files are named as follows: libmysqlclient.a. Well in the C API that comes with MYSQL it is named mysqlclient.lib. It says it was compiled with VC5.0. Secondly, when I include my_global.h, I get a bunch of errors. One is that my_config.h cannot be found. When I look for it, it is no where in the include folder. I have gone through the MYSQL manual and followed all of the examples, but keep having problems. I have a code file as follows that will not compile and link:

Code:

#include <my_global.h>
#include <mysql.h>

int main(int argc, char *argv[])
{
   return 0;
}

That will not even compile. If I take the my_global.h out, it will compile. But then I cannot get it to link. I add the -lmysqlclient but it says it cannot find the library. It is name as follows mysqlclient.lib. I don't know what to do. I have fought this thing for days. Any suggestions?????

Thanks,
Kendal

my_global.h and mysqlclient.lib came with mysql when I downloaded and installed it. The C API was included with mysql. The problem is getting any program that uses the C API to compile and link with a C compiler. I am using the gcc compiler. If I include my_global.h, I get compiler errors along the lines of missing header files, redefinition, syntax errors with the headers files. If I remove my_global.h, I get undefined reference linker errors. I am pretty sure that that has to do with linking the mysqlclient.lib. The mysql\lib\opt directory has the following files:

libmySQL.dll
libmySQL.lib
mysqlclient.lib
zlib.lib

I add the include directory and the lib\opt directory in to the compile and link commands, but still get the errors. Any suggestions?????

Thanks again,
Kendal

I have tried many variations, here is one:

cpp test.c -o test.exe -I"c:\mysql\include" -L"C:\mysql\lib\opt"
-lmysqlclient

The main problem with this command is the linking of the library. The path is correct, the compiler says it cannot find the library. I have a list of the libraries above. I have tried many variations of the library, libmysqlclient, mysqlclient.lib, libmysqlclient.lib, just about everything I can think of. Thanks for taking the time to look at this post.

Thanks,
Kendal

http://darkstar.ist.utl.pt/mysql/doc...compiling.html

http://rsynnott.f2g.net/mysql.html

Scroll to the bottom of both pages.

I have read through those pages and followed the instructions. I have tried downloading the client lib for mingw, i have tried using pexport and the dlltool. I have tried all of that and I cannot get anything to work. It still cannot find global.h. If I remove the myglobal include line, I still get linker errors. Here are some of them:

Code:

Compiler: Default compiler
Executing  gcc.exe...
gcc.exe "F:\Dev-Cpp\Code\MYTest1.c" -o "F:\Dev-Cpp\Code\MYTest1.exe"   -fmessage-length=0  -I"F:\Dev-Cpp\include"  -I"F:\MySQL\include"   -L"F:\Dev-Cpp\lib" -L"F:\MySQL\lib\opt" -L"F:\MySQL\lib\opt\New" -lmysql
In file included from F:/MySQL/include/mysql.h:57,
                 from F:/Dev-Cpp/Code/MYTest1.c:1:
F:/MySQL/include/mysql_com.h:116: parse error before "SOCKET"
F:/MySQL/include/mysql_com.h:116: warning: no semicolon at end of struct or union
F:/MySQL/include/mysql_com.h:135: parse error before '}' token
F:/MySQL/include/mysql_com.h:135: warning: data definition has no type or storage class
F:/MySQL/include/mysql_com.h:167: parse error before '*' token
F:/MySQL/include/mysql_com.h:168: parse error before '*' token
F:/MySQL/include/mysql_com.h:169: parse error before '*' token
F:/MySQL/include/mysql_com.h:170: parse error before '*' token
F:/MySQL/include/mysql_com.h:171: parse error before '*' token
F:/MySQL/include/mysql_com.h:172: parse error before '*' token
F:/MySQL/include/mysql_com.h:173: parse error before '*' token
F:/MySQL/include/mysql_com.h:175: parse error before '*' token
F:/MySQL/include/mysql_com.h:176: parse error before '*' token
F:/MySQL/include/mysql_com.h:180: parse error before "s"

In file included from F:/Dev-Cpp/Code/MYTest1.c:1:
F:/MySQL/include/mysql.h:165: parse error before "NET"
F:/MySQL/include/mysql.h:165: warning: no semicolon at end of struct or union
F:/MySQL/include/mysql.h:202: parse error before '}' token
F:/MySQL/include/mysql.h:202: warning: data definition has no type or storage class
F:/MySQL/include/mysql.h:211: parse error before "MYSQL"
F:/MySQL/include/mysql.h:211: warning: no semicolon at end of struct or union
F:/MySQL/include/mysql.h:217: parse error before '}' token
F:/MySQL/include/mysql.h:217: warning: data definition has no type or storage class
F:/MySQL/include/mysql.h:232: parse error before "NET"

That is coming directly from my Dev-C++ compile log. I just cannot get anything to work. Any suggestions

Thanks,
Kendal

They are compiler errors.
It seems that your compiler is having trouble with this structure:

Code:

00113 typedef struct st_net {
00114   Vio* vio;
00115   my_socket fd;                                 /* For Perl DBI/dbd */
00116   int fcntl;
00117   unsigned char *buff,*buff_end,*write_pos,*read_pos;
00118   char last_error[MYSQL_ERRMSG_SIZE];
00119   unsigned int last_errno,max_packet,timeout,pkt_nr;
00120   unsigned char error;
00121   my_bool return_errno,compress;
00122   my_bool no_send_ok; /* needed if we are doing several
00123    queries in one command ( as in LOAD TABLE ... FROM MASTER ),
00124    and do not want to confuse the client with OK at the wrong time
00125                       */
00126   unsigned long remain_in_buf,length, buf_length, where_b;
00127   unsigned int *return_status;
00128   unsigned char reading_or_writing;
00129   char save_char;
00130 } NET;

However, this was taken from the web and is probably different to your version so please paste your version from mysql_com.h 116.

My guess would be that the SOCKET (alias my_socket above) type is not defined. Try including <winsock.h> above all your other headers.

All the other errors probably relate to the NET type not being declared.

You were right. I added the winsock.h and that corrected the compiler problems. I could have sworn that I tried that before and it didn't work. Anyway, after that I tried compiling a complete sample and got some linker errors. So I went to one of the links you previously posted and downloaded the .a client library for mysql. When I added winsock.h and used the downloaded client library, the program compiles and links. So a combination of both makes it work for the time being. If I run into any more problems with mysql, I will post back on this post.

Thanks a million,
Kendal

Try this
gcc -o outputname infile.c `mysql_config --cflags --libs`
Hope this will help